I think MUA support would be a big selling point on higher end tablets.
My family has an iPad 2, I never use it because I can't personalize anything. I bought the Nexus 7 to be mine. At $200, I'm happy with single user. But if I'm to shell out $600 - $800 on a tablet as a laptop replacement, or home entertainment device, I don't want to have to share email (or log into a web page every time I want check email), and I don't want to listen to my kids fight over you spent the points I earned in game "x". And I don't want my kids hitting the buy button when my credit card is in the Play store.