I believe from what has been said here that the final version will just be a normal windows update of the beta. Can't recommend it highly enough. If you've ever run a PC with no AV (not recommended) you'll know how quick it all is, booting up and so on. This doesn't seem to impact at all that. More info here,click here
:) After trying others including paid for security packages over the years the Microsoft one wins hands down for me, particularly so for a notebook with more limited resources. It also promises freedom from upgrade/update issues as new versions are released unlike others, and should :) offer complete compatability with Windows.