If Vinokourov returns to lead Astana as a GC contender, and LA leaves with Leipheimer, Horner, Popovych and Bruyneel, then surely AC has to leave Astana as well.
He doesn't seem to need that strong a climber to help him out in the mountains. I doubt Valverde wil be a good partnership though - they migth wok together when they're on different teams but when they're in the same team .... ?