I believe that other than the login account, the stores are different.
I would love unified apps like iPhone/iPad though - buy once. Also the store login on the phone should be separate from the main user of the phone - so you can buy a family game like on the iPhone. You can do this on RT/Win8 PC, but not to the phone.
Loving my 920, but yes, there are some things the done better elsewhere... Microsoft needs to catch up.