This has been thrown around countless times. You're new, so I won't be harsh with you. (Have a fishy stick by the way: http://images.uesp.net/c/c4/Fishystick.jpg)
I don't think its a very good idea, honestly. Bethesda game studios has their few games they work on and they should keep it at that. I'd rather them produce a few amazing games a decade than countless piles of crap. An open world middle earth game is a good idea, but bethesda doesn't need to make it.
LOTRO is kinda open world. Not entirely, but sort of.