In my experience, the kids will bring the toys to where ever you are because they want to interact with you while they are playing (you have years of 'look at this mom, look at this' coming). So even if you make the 3rd bedroom a toy room, you son will probably bring the toys to the LR (not yet, at 11 months, but as soon as he can walk and carry things). And your living room will be a play room whether you want it to be or not.
My solution was to get a nice bookshelf and pretty cloth bins that fit on the shelves and the toys are all stored in there. There are times when the LR is a wreck with toys - but it's easy and quick to clean up when everything has a place.