5 megapixels camera and 64 GB are things that will come for sure I guess. 3 is fine, but 5 is better. 8 as a maximum, more megapixels don't work very well (yet) with todays lenses.
I guess also some new chips: better for the environment (like Apple always is promoting) which consumes less energy. In that case the battery will last longer, even if they use the same battery as in the 3Gs but of course they will update the battery some how so much longer battery life. WiFi 802.11n (like now found in the iPod Touch even though it isn't activated yes).
Radio will come to the iPhone to for sure, maybe through some update or with the new iPhone. Multitasking once has to become true, and I think there's even little hope for flash now it's asked more and more by people. Sure, HTML5 is great, but for the timebeing I want some flash.