Well, Most phones will have either 2.1, or 2.2/Froyo. Version 2.3/Gingerbread was released this week on the new Nexus S. Nexus phones are stock Android phones so they will always get the latest updates. The G2 is stock too, but I am not sure about their update timeline. If you do not get a stock Android, you have to wait for the carrier/manufacturer to issue an update.
I most definitely miss the cards, that was one of THE Best features, EVER! However, it looks like version 3.0/Honeycomb may introduce cards, or something similar (Google hired webOS UI designer Matias Duarte). I miss synergy as well, although you can still link accounts -- just manually.
I do like the Wealth of apps for Android, and WIDGETS! I cannot live without them now. Plus, all of the customizations for the OS are crazy (various app replacements, app enhancers, live wallpapers, Launchers, etc.), and get better with rooting to unlock even more possibilities. WebOS is very polished, but Android is Highly customizable. I'll stick with an Android phone, and pick up one of those PalmPads to fill my void.
S/N: I left my Pre 6 months ago to get an Evo, then moved to an Epic 2 weeks ago. Evo already has 2.2, bigger size (4.3" screen), and slightly better cams (spec-wise), but Epic has a very vibrant screen (4" SAMOLED), a slightly better fit in the hand, and the Hummingbird chip inside... BEST on the market, even better than iPhone4.