Nah, they are not connected, that's the point. There is an infinite amount of virtual MMO worlds out there, all hatched from the seed, and the ALO+SAO server is only one of them, possibly the biggest (tho no one actually says that).
Asuna was never a part of the game, so I guess she designed a new character when registering.
Also yeah, wiping the stats wasnt that cool, I think so too. Also, am I the only one who thinks that Kirito's SAO character was a lot more badass than his ALO char? I have no idea why would he choose the latter over the old SAO one. Well, the whole "new world, put old things behind me" does have a point, but still... The others remained with the SAO char, I was a little disappointed that he didnt.