I'm really curious about this. There's no information about when specific regions are going to be supported, so some people will have no option but to import. We also don't know if regions are identified by IP or something else. If they do import, will their Live accounts work? Will people have to connect through a proxy and then create a Live account for that proxy's country?
Anyway the tweets don't say clearly that people won't be able to play games in the unsupported regions. They just say they won't have the full experience. What is that supposed to mean?