Ok so I have a prediction for the new iphone and it might make a lot of you unhappy. This is not based off of any rumors or facts really for that matter, its exclusively my opinion so please don't flame me lol.
I think that we will be getting a 32GB 3G in June or sometime during the summer and the next generation iphone won't be released until a later date such as november-decemeber or maybe even 2010.
Reason: I think the new iphone will be completely remade with completely new innovation to compete with other phones. As you remember the first iphone did this. The 3G did not because it only added two features that the first gen didn't have: 3G and GPS. There was also new software but this was compatible with the first iphone so all was fine and dandy. I really think that there will be such a big hardware change (most likely for multitasking) that there will be a new breed of iphone and it will not use the same software as the other two generations, just like how there is different software for different ipods. I also believe that apple will hold off because wireless providers are testing out their 4G and they don't want to do what they did with the first iphone, and leave out a very important aspect to a smartphone--fast internet.
Summary: The next generation iphone is not coming out this summer and will be released at a later due to a major overhall in hardware/software.
Note: I could be WAYYY off and this is probably just wishful thinking but it still is possible