Yeah I am waiting to upgrade to the 32 GB model when it comes out, and actually, Im not that impressed with the "iphone 3G." Currently my region doesn't have 3G, and I have GPS in my car, so the GPS in the phone isn't a real selling point. The back of the phone is now plastic, I prefer my "old" iphone's metal back.
That's where the problem is with me. I have my Treo (unlocked), here in the US with an AT&T SIM, when I'm in the Philippines like I was the past two weeks, I pick up a local SIM for P65 (about $1.50 US) and only need to own one phone.
For me, I use my phone for too much, and as a software consultant, it's beneficial if not necessary to my career to keep on top of the latest and greatest. My firm is very close to Microsoft and usually gets the new version of everything when it comes out. Disney says they can access their whole SharePoint portal with the iPhone 3G, it now supports direct-push email and integrates well with a variety of other services like GMail. Bam! I'm sold! That, and I was considering buying a new video iPod anyway so my wife and I could each have an iPod for music, and we'd both be able to share the iPhone to watch videos with when travelling. It appears that the 20+ TV shows and 4 movies I downloaded on iTunes only take up about 13 GB, so 16 GB is a little paltry, but not too bad. I wish it were more, but that could get me through a trip. I suspect that the plastic back is another cost-cutting measure to make the price more accessible to the masses. I immediately cover my phone in some sort of ruberized skin anyway, so it's not a huge deal for me. I actually think the GPS capabilities and 3G are pretty cool (I can see it coming in handy when I'm on foot and need to find a nearby restaurant with Google Maps), but I guess some of the main innovations with the iPhone 3G are some of the lesser appreciated hardware features. Battery life got freaking sweet (300 hours standby, up to 10 hours talk time, 5 hours 3G web surfing, 7 hours video, 24 hours audio), while call quality improved and download times beat competing phones by 36% because of their 3G/browser.
In case you hadn't heard: Data plans for the new iPhone are $10/month more than for the old iPhone. So the minimum plan is $70/month instead of $60/month.