I'm actually worried that Eminem will block her. He is a real threat to ARTPOP getting #1. Recovery wasn't even a 4th quarter release and it did over 300k second week. I think it's very possible that Eminem could do 400k second week with holiday sales. Gaga won't be seeing BTW numbers. I'm honestly not expecting her to do higher than 400k first week.
I think he can block her. I mean with BTW she made 1mil+ first week and thats when her single sold like 1mil the first week (right?). I don't think she can do it with artpop.