Whats the deal with Media Hub Galaxy Tab 7


My recent Media hub update ( Samsung Galaxy Tab 7 Android 2.3 ), now wants me to create a samsung account. I guess thats not too bad, but why not just seamlessly integrate with my Google Android account?

Do I have to do this to buy movies at all, or can I buy them directly from Google Play appstore?

If I buy them from Google Play appstore, what will they play in?