The iPhone is a mature product. There's not much more that can be done to it other than faster processors, more capable GPUs, etc. These will appear when they can be incorporated
without sacrificing battery life. That is the one figure of merit Apple intends to stay on top of the pile with, and since it's the one that matters most to consumers, I think they're right to do so.
As for LTE,
according to BGR, the Thunderbolt has 4.5-hour battery life running 4G (and no way to shut it off). You won't see an Apple 4G phone until that situation can be rectified, which it apparently can't with any available radio today.
The
real upgrade will be iOS5, and I can see them previewing it at WWDC, putting out an upgrade sometime later, but not announcing new hardware until September. This gives developers 3 months to write apps for it and get all the kinks out, and people who upgrade their iP4s with iOS5 are going to be getting much more of a new phone than any hardware change would give them at this late date.
Let's speculate about next year while we're at it. It may be September before anybody who wants an iPad 2 can get one. Apple may very well decide to start the clock there on the iPad2's one-year life cycle, and starting next year, announce
all the new iOS hardware (iPad, iPhone, iPods) at a huge blowout event in September, after announcing the new iOS software at WWDC in June. That may be where the "September iPad announcement" rumor came fromnot this year, but next year.
That would also leave the other half of the year for any OS X and Mac announcements, without the iPhone/iPad frenzy sucking all the air out of the room.
) instead of new hardware to the same two companies would be better in the end for Apple and everyone else in who are stuck in contracts with other carriers such as Sprint, T-mobile, and U.S. Cellular. 
