I think it'd be a lot more fun to NOT inherit all our crap we've built up once monsters are released. We didn't fight for this garbage.
If you're really attached to your buildings then have them, the map backups can be downloaded on mc.injate.com/backups now - you won't keep your player inventory if you put it in your SP folder. you have to port the player/name file to the SP file format/location (I have no idea how to do this, don't ask me).
