I went the GSM route .. I am and have been a sprint customer for about 10 years now (with the "Simply unlimited" plan), I decided about a year ago I was going for the Pre3 even before my Pre- mostly died on me earlier this year(and of course before the Pre3 was announced - I was going to move to whatever came after the Pre2 since Sprint didn't pick up the Pre2 - I was hopeful they would pick up whatever replaced it)
So I have an order out for a pair of pre3s (not sure if I will get them for another couple days).
I ordered a Pre2 which was around ~$400 I think (couldn't find a new one cheaper at the time this was a few days ago), should get here today.
And I signed up for AT&T on Sunday to get a Veer for $0.01. I figure since I'm going with AT&T anyways might as well get a free phone. I never really liked the Veer form factor for daily use my hands are too big but I won't turn it down for a penny.
I've been using a Sanyo feature phone since January while I've waited for the Pre3 to be released.
I decided on GSM mainly so I could switch the SIM between phones.