No. There appears to be very little reason to. The only reasons I could possibly understand are for the faster processors and faster HSPDA. However AT&T isn't suppose to roll out those towers until late 09, which most likely means a few large cities will get them in the beginning in '10 (speaking in AT&T terms here).
I was a little worried about apps appearing that can only be used on the 3GS due to the new processing power but it doesn't seem like too much of a boost. I never used video on my old phone, and a compass is just blah.
No reason to upgrade here. If I hold out a year, perhaps apple will have a more substantial upgrade or they'll come out with an iPhone for Verizon since AT&T's deal ends in '10. Signing another contract would just force me to keep AT&T's service for another year. Perhaps if they had some sort of trade in/cheaper upgrade I might have been enticed, but $200 extra for a small upgrade....no thank you.
