Are convergence devices the wave of the future?

Frankly, convergence devices scare me. That's because I have a vested interest in the continued existence of MP3 players and PVPs as standalone devices. Luckily for me, cell phones have mostly failed to offer a truly enjoyable music browsing experience thus far. They don't have a lot of built-in memory (though the increasing inclusion of built-in memory slots is certainly cause for concern...mine, anyway), and their batteries aren't yet robust enough to safeguard against that ever-pressing issue: draining your power rocking out and then being unable to make or receive important phone calls. So I can rest easy knowing that my job is secure for at least a little while longer. But as I like to stay on top of things in that arena, I thought it would be wise for me to attend a SXSW panel titled The Truth About Mobile & The Future of Personal Devices. The question on my mind: is the iPhone just the beginning? (Well, no, it's more like the middle, but you get my drift.)
Did you know that 250 million Americans subscribe to some sort of cell phone service (that's a whopping 85 percent of the U.S. population)? MP3 players have nowhere near that kind of prevalence, so it's no wonder content providers (music services) want media players on handsets. But do all Americans want a complete multimedia device--camera, music player, video player, gaming device, e-mailer, and cell phone all in one? Not necessarily (phew!). According to panelist Patrick Moorhead of R&D Advanced Marketing Solutions, it's a matter of substitutes versus complements, which incorporate various factors: battery life, memory capacity, camera resolution, and screen resolution. Substitutes are those devices that can be successfully converged, while complements refer to features that complement the main purpose, but wouldn't be a suitable substitute for both devices. Based on Moorhead's beliefs, a camera phone is not a suitable substitute due to poor camera resolution, a video phone is not a suitable substitute for a video player due to inadequate screen resolution and memory capacity, and a gaming phone is not a suitable substitute for a gaming device due to battery life and processor power. However, he does believe a music phone is a suitable substitute for an MP3 player. Oh dear.
Well, I'm still not worried. I tend to disagree with that last statement, mostly because the majority of phones don't offer the user experience that a quality standalone MP3 player does. Also, it's interesting that he used the iPhone as an example, but still made the statement that a phone couldn't replace a video player. If Apple is to be trusted (debatable), the iPhone should make a pretty decent video device, with its ample wide screen (when flipped into landscape mode) and virtual interface. One thing is probable, and that is the iPhone's multimedia user interface will be excellent. OK, now I'm worried.