My guess is that the Android platform won't initially outshine the iPhone's total hardware/software package (e.g. I bet HTC doesn't out design Apple for starters) but the biggest thing keeping me away from iPhone is the proprietary nature of the platform.
With Android, I'm at least relatively certain of an upgrade path, and if I start buying software for it I think the software would be portable to other adroid-platform hardware and allow me hardware freedom that the iPhone platform doesn't.
Ultimately, I suspect the open platform will win, but the iPhone got a big head start and it really depends on the app ecosystem to me. Right now I don't have an iPhone because they don't have the gps software I need on that platform (and may not even permit it) and because I would have to hack it to even use it in Costa Rica. An open source platform like Android is far superior on a theoretical level and I think over time the open platform will win because of that freedom.
If I were a mobile software developer I'd code where the userbase is, but I'd be hoping the userbase is on the open platform. I think if enough developers take up the platform it will eventually supersede Apple's walled garden.
By the way, can't you wait a few weeks out of contract before deciding? I don't think you need
to sign a new one to maintain service and that way you can at least wait till this phone is out before deciding.