Thought about this myself and was sooo close to ordering a HTC device myself. Contemplated a HD2 but WinMo is always going to be horrid, regardless of the Sense window dressing and the Passion/ Bravo/ Nexus one is effectively the same thing but running Android. The downside? The camera.....HTC have a nasty reputation for fitting utterly terrible cameras to their phones. Even with the pink issue fixed on the HD2, the picture quality is merely 'ok' with colours not being quite right and the images being grainy when viewed off the phone such as on a PC. The Nexus one suffers the same pink issue that the HD2 did and they're havng to release a fix in the next update which goes to show the same underlying issues on both OS's regardless of whether it's WinMo or Android. Poor, and I wouldn't be surprised if the Passion has the same problem when it finally appears which is naff on HTC's part.
The X10 will be the first Android device that actually sports a proper camera, and judging by the sample shots I've seen it looks to be good. Coming from N series Nokia's recently I could not bring myself to compromise on camera quality.....I use it far too much. Sure, if you want truly good pictures you buy a dedicated point and shoot but the best kind of camera is the one you have with you which makes it an essential requirement for me.