Well as I've said elsewhere, projecting, it *seems* like it would be a no-brainer fit for MS - Home Studio is the perfect, drop-in freebie Garage Band killer (err, competitor). Artist/Professional/Platinum - well, it may not make any sense to maintain two versions (and in terms of features the difference has been shrinking as most new features for the past while have been cross-version), so combine those into one solid Logic competitor (likely dropping most of the third-party content), and MS gets a big dose of creative cred with very little dev work, a codebase that's already tightly integrated into their audio world and, ideally, a great development team they already know and work with.
But who knows if it looks like that from where they stand?
edit... of course, they would grandfather the existing Lifetime members (and anyone with an owned license for Platinum) into an initial license for the paid version...
edit 2... in related news, pigs can reportedly fly now!