... Are there plans to move WHS 2011 to a cloud based service? If so what are the costs involved? Or are there plans to do some kind of upgrade to a "WHS 2012" OS?
No, and have you looked at the top of the forum, specifically at the announcement that Windows Server 2012 Essentials has released to manufacturing?
Note, however, that the storage of huge volumes of data online is not part of the plan. You will store your data on your server, and access it from any device with network access.
I'm not on the WHS team, I just post a lot. :)