Bethesda biggest problem is that they are a known PC studio, not just amongst the consoles. A ton of Nintendo gamers are also pc overlords and have probably already played Skyrim, whereas your typical playstation or xbox owner doesn't usually (in my opinion) have a beast pc, so that is the only way you'd be able to play something like Skyrim or Doom. In regards to the op, based on what I just said here, I really don't see Skyrim doing over 500k. Honestly, if it does well it will be in the 300k range.
Super Bomberman R is on track to pass 500k, you think Skyrim will sell less than that game? 300k seems pretty low for a crazy popular game with the novelty of being truly portable for the first time.
Super Bomber R was a new game. Skyrim is old. And it's been released many times before now, including with new additions. I really don't think it's going to sell great. Doom and Wolf have a better chance since they are newer games.