What could the Verizon iPhone bring us?

In less than 24 hours, and just over four years after the original iPhone was born, Verizon Wireless is poised to announce its own version of Apple's device. Needless to say, it will be a very big deal for the iPhone in the United States. Not only will it end AT&T's monopoly on the popular handset, but also Verizon Wireless stands to gain millions of new subscribers who've been waiting eagerly for years.

Indeed, it will ensure a very good year for Big Red. Even as it was enjoying a hugely successful CES 2011 with a gallery of 4G handsets and the award-winning Motorola Xoom tablet, the carrier told reporters last Friday that it would be sharing "the latest news" January 11, tomorrow, at 11 a.m. ET at New York's Lincoln Center. The invite didn't mention an iPhone specifically, but given the avalanche of leaks in recent days, all signs on the wireless Magic 8-Ball are pointing to yes.

Yet, even with the big news almost confirmed, there is still plenty we don't know. Just what will the Verizon iPhone offer, for example, and how will it differ from its AT&T counterpart? At its core, it won't vary much. It should have the same design and it shouldn't offer any new features. Remember that Apple is all about consistency and a uniform experience. That said, however, there are a few factors to keep in mind.

Network
This, of course, is the biggest "what if." Given AT&T's iPhone troubles, many consumers are looking to the Verizon iPhone to cure their wireless woes. This is understandable, but I'd caution against thinking that Verizon's iPhone experience will be without any problems. Sure, Verizon runs a very tight network ship. You can get it almost anywhere, you can keep a call once you have it, and the carrier continually wins awards from third-party sources. That success has earned Verizon a lot of respect for its voice network and it will hold on to that image zealously. What's more, Verizon has undoubtedly learned from AT&T's misfortunes and it will not follow its rival in underestimating the infrastructure it needs.

Still, you can't forget that you're using a cellular network that's subject to the same factors that affect service on AT&T. Your location, urban density, geography, and how many users are on the network at one time will continue to affect service. Though I hear fewer complaints from iPhone users outside of urban areas, iPhone users in other countries have grumbled. A phone's reception depends on more than just the carrier, as the phone itself also plays a part. We've used plenty of other AT&T smartphones and don't get quite the experience that we do on the iPhone.

Data brings its own concerns. Though AT&T's data network is faster than Verizon's in theory, in practice it hasn't kept up with the massive data demands of so many iPhone users. Verizon's 3G network has better coverage, but we'll have to see if it can handle an equally huge boost in demand. On the upside, Verizon has boosted capacity and it has used Android users as a test group for demand. The Wall Street Journal reported last year that the average Verizon Android customer uses more data than the average AT&T iPhone customer, but its real test is yet to come. When you're dealing with such high expectations, the only way to go is down.

So what's the final answer? Well, as CNET's Erica Ogg and I said in October, we just can't guarantee at this point how a Verizon iPhone will perform. Customers should see better service, but just how much better remains unknown. Verizon likely will gain customers in waves, which means the buildup in data demand will be gradual. On the other hand, Verizon iPhone customers won't use any less data than AT&T users, so we could know very quickly. Until then, though, proceed with caution and don't expect miracles. If you live in a location where you currently have great Verizon coverage, you may have a great experience. But then again, you may not.

Will it be 4G?
Despite Verizon's intense focus on its new 4G network, and persistent rumors that the Verizon iPhone will support LTE, I think this is unlikely. Apple loves to control the user experience, so I can't imagine that it would be eager to jump on a network that doesn't cover the whole country and it still untested by smartphone users. Until Verizon ramps up its 4G network fully, Apple will wait to ensure that it works and works well. Also, an LTE-only phone would leave out all those Verizon users not in a 4G market, and Apple is never one to pass up market share. There is a possibility that Apple could put an LTE chip in the phone for future use--you can't upgrade a 3G handset to 4G with just a software fix--but I doubt that as well. Apple would much rather have you shell out money for an upgraded model in a few months.

About CDMA
A CDMA iPhone will not be able to transmit voice and data simultaneously. So all those Apple commercials that show a user looking up a restaurant while on the phone won't apply here. The CDMA Development Group (CDG) will make simultaneous voice and data commercially available in the first half of this year, but we don't know exactly how and when. When I asked a CDG spokesman for more details last month, he didn't have more to say.

If the Verizon iPhone runs only CDMA, you won't be able to use it in many countries outside of the United States. That's a big deal for world travelers, particularly in Europe where GSM rules. The carrier could, however, release a dual-mode handset that uses both CDMA and GSM. Finally, CDMA phones in general have shorter battery life than GSM devices. That may not turn out to be the case with a Verizon iPhone, but it's possible.

Design and software
As I mentioned, the Verizon iPhone should look no different than the iPhone 4. That is, with one small exception. I would not be surprised if the infamous gap on the iPhone 4's left side disappears. Despite Apple's claims that "antennagate" was a media-created phenomenon, CNET encountered a significant drop in performance when we touched the gap while on a call. On a related note, a popular, and not totally crazy, conspiracy theory suggests that Apple is saving the elusive white iPhone as a Verizon exclusive.

The handset should be the same inside as well. Again, Apple wouldn't remove a feature, and its desire for consistency means it wouldn't add functionality not available currently. And don't expect to find any Verizon content like V Cast. Verizon may have passed on the original iPhone because it didn't want to cede control to Apple, but I'd guess that the carrier warmed up to the idea.

Pricing and availability
CDMA components can make a phone more expensive, but Apple will dissuade Verizon from pricing the iPhone differently from AT&T (there's the consistency again). Yet, plans are a different story. The Wall Street Journal reported today that Verizon will adopted unlimited data plans for the iPhone, a practice that AT&T abandoned last year in favor of tiered plans. The exact release date is still a mystery as well, but rumors persist that Thursday, February 3, will be the magic day.

CNET will bring you live coverage of Verizon's event tomorrow, January 11, at 11 a.m. ET, so be sure to check back for the full story. In the meantime, tell us what you're expecting from the Verizon iPhone.