I lived that myself when my sis and I were kids and can totally sympathize with both boys . . . and you! Do you have enough room to keep both beds on the same wall and add a tallish bookcase with a back on it between them? If you turned it sideways it would act like a very functional room divider. The neat kid could use the shelf side to organize and display his sports memorabilia and equiptment. Attaching corkboard and/or magnetic board(s) to the backside of the shelves would give your artistic kid a place to display his artwork. Or, better yet, how about 2 identical bookcases, end to end, dividing the room down the middle a bit more? Have one facing each way to give the boys some better room division plus added shelf storage and display space? A smallish shelf attached to the backside of the bookcase closest to the wall would give that son a small nightstand area, if he needs it. Wall lamps could be used over each bed for reading.
Lynn

I was going to suggest what Lynn did. Some sort of visual divider would help a lot. And when your sons are older, 13 and 10 or 16 and 13, they will appreciate the semi-privacy.
You could also do a wardrobe divider like this. Follow the link at the bottom f the article for more pictures.

Here is a link that might be useful: Wardrobe as room divider in boys room

It might be best to give up on the symmetry. :)

If you have in Ikea around, look at their Expedit stuff. They have some large (and it comes in RED) bookcases that can serve as room dividers. They aren't fine furniture but should be sturdy enough.

It might help ~ and generate more responses ~ Tinker, if you post some pics of the actual room for us to see.