As a team with Protour license (which Astana is at least at the moment, and most likely also for next season), they are automatically in all 3 big tours and majority of big races. Things are a bit more complicated in cycling, so some big teams or teams with big players (like Di Luca's LPR for example, let's skip last week's news about Di Luca now :)) don't have Protour license, so they depend on invitations from organizers, while teams with Protour license are automatically invited. So at the moment, I don't see reason why Astana wouldn't be there.
As far as Contador goes, I don't think it's that bad option if he would stay with Astana. Even if Vinokurov will be back, Contador will most likely be the only #1. Vinokurov's attitude is a whole lot different then Armstrong's, so I don' think this year would repeat, and with Vinokurov back in team, I'm pretty sure Kazakh's sponsors will open pipe with money a bit more, so I doubt there would be money problems like they were suppose to be this year. And I say suppose to be, since I have feeling this was another media thing produced by certain people on or around the team.