The iPad is Apple's bold answer to the Netbook, but that doesn't mean it can replace all ultraportables (yet).
Most Netbooks, even low-end ones, now have webcams enabling basic video chat over Skype or any other program. The iPad, however, does not. We wish the iPad had a camera and iChat, especially since it would make the tablet a unique communications device to rival the iPhone. Perhaps cost was a factor, even though most Netbooks manage the feat in a package under $500.
While Steve Jobs called the iPad "the best web experience you've ever had," there is a big missing piece right now, and that's the whole web. Browser-based apps and Flash-driven content are a huge element of cloud computing and of many websites. While HTML5 is rapidly gaining ground to offer alternative streaming video solutions for the iPad, and sites like Netflix and CBS are crossing over to provide iPad video solutions, the selection of content right now doesn't come close to matching what's available via Flash. While Atom Netbooks can be slow and stuttery when playing web video, at least they can.
Most people aren't programmers, or anything close to it, but most Netbooks do run on a full Windows 7 OS that can be used for programming or modification. Linux-based Netbooks are even more hack-friendly. You can even install Mac OS on a Netbook, should so you so wish. For the friendly hackers out there, that's a dealbreaker on the iPad.
No USB ports on the iPad mean no connecting cameras or other peripherals without a $29 camera attachment dongle, and even then, you can't simply drag files to the desktop like you can on a Netbook. It could be a drag if the iPad is meant as a portable computing replacement for bloggers. Netbooks have at least 2 USB ports standard.
Sure, the iPad is slim, attractive and very showy, and boasts a significant battery life. But its battery is fixed, while a Netbook can not only swap its battery, but upgrade from a three to a six-cell or more.
Install CD media (or any media other than from an App Store)
With the addition of a simple USB DVD/CD-ROM drive, disc-based software can be installed on a Netbook even without an optical drive built in. Netbooks can also install files off USB drives, or via any other input method. The iPad wasn't designed with this flexibility in mind, but it's still nice to be able to do.
Yes, the iPad has a virtual keyboard, and even a cool keyboard dock that turns the tablet into a quasi-desktop device. But the dock can't be used for lap typing, and the iPad lays awkwardly flat on a table unless you're using an elevated case. For long-term writing on the go, a physical Netbook keyboard with an attached angled screen still wins.