^ this. No syncing with cables. Just over the air, I guess with 3G or wifi.
while the android market is on the phone, they also have a web based site, like the apple app store on iTunes. I just think its kind of neat that it can do that. Sometimes you may want to browse for apps on a larger screen like you can with music, movies TV shows and even apps in iTunes
I'm not sure as I only have one android device and an iPad. I don't see why not.