The problem with getting an Android phone is the landmine field. Which is a shame since it really shouldn't be.

You have to ask. Is the device going get a firmware update. Which is dependent on the carrier and/or manufacturer. It's not something where you just take an image or download it when Google releases it. Some devices out there will never get an update sadly. The alternative is to find a device with a community set around hacking it (usually the big popular ones like Droid, Evo 4, etc..)

It's kinda weird to think the N900 is closer to running Froyo than most Android phones will ever be.