I'm waiting to see how the Epic 4G shakes out - on paper, that's the best / equivalent option for a phone good today and with the processing power to survive into the future.
Out of the box, there's a known GPS issue that Samsung is promising to fix in September - that and any early reports on the keyboard reliability are what's holding up our immediate ordering, but your mileage may vary.
If you love your Evo, then the overall appearance of the Epic might turn your stomach - LauncherPro will be the first thing that phone will get at our house!
(PS - My wife's a Moment (Android) user and she's our Epic target.)