However, keep in mind that your video chat is limited. Skype doesn't have any video chat support. Qik sucks. Fring is limited to mobile devices only. ooVoo Mobile is left as the only decent solution, if any of your friends use that. I'm hoping that Google releases a Google Talk update on the Market with video chat support.
I'd get the Nexus S. It has all the nice things about Samsung hardware without Samsung being tied to the device for software support. 4'' is really the perfect screen size. It's spacious, but not as big as say the Evo. You've also got the nice Super AMOLED screen. The only real downside to the Nexus S is that there is no microSD slot. You're limited to the 16 GB in the box.