Let the hive mind of Engadget get that for you.
"I'm in the market for a new phone and money isn't a limitation. I'm also not partial to any particular US carrier, but here are some of the features I'd like to have: WiFi, GPS, good coverage in lots of places, push Gmail (a must!), physical keyboard (a must!), a touchscreen, decent battery life and a relatively slim body. And please, nothing that has a fruit logo on it. No offense to the fruit fans, though. Thanks!"
Re Ubuntu:
Both Maemo and Ubuntu are based on Debian, and so use the same excellent package management system (APT) to synchronize versions and choose features. Maemo is smaller (duh!), with some extra goodies for small touch screens. So I'm not so sure that the horse of different color you are referring to hasn't already shown itself... :)