The latest iPhone rumor--based, as per usual, on a thin thread of evidence--implies that new phone will pump-out HD quality video, and even have an HD-compatible screen. This is entirely plausible, and it begs the question: What are the implications of Apple making such a move?
While going HD may seem like a no-brainer, a change of such magnitude is a delicate issue for Apple to navigate.
All of the currently existing Apps are written for the current screen size--480 by 320 pixels at 163 pixels per inch--and it's unclear what a revolutionary screen-change would mean for older apps. Would they simply run in a letterbox automatically? Would they need to be re-written for the new display? App creators may want to optimize, but that could require significant development work. All-in-all, the change would have big implications for the App Store, which is a primary reason the iPhone remains so successful.
A revolutionary next-gen iPhone packed with a new 720p screen and extra tech implies a similar or even more expensive device, which would have a significant impact on sales. The iPhone is already expensive, its high price is the reason people often cite for not buying one. An evolutionary iPhone, without HD, could go on sale at a lower price, especially if Apple manages to shrink manufacturing costs and strike deals with electronic component suppliers.
We may not have to wait very long to find out what happens: Apple could be planning a May launch, just to kill the buzz on the Palm Pre.