Setting up a toy corner in the lounge room sounds wise, but having a toy storage system you can roll under the couch is even better.
At IKEA Hacker, Alix details how adding some wheels to some IKEA Komplement wardrobe drawers created a snug-fitting toy system that rolls away when it's not needed. You might choose different items (Alix even had to do some literal hacking with a saw to get the drawers to fit), but it's a great concept if you're looking for toy storage. This kind of approach has a triple-benefit: you've got an easy way to clean up, you're making good use of the space, and having something under the couch makes it less likely that kid stuff will roll under there and be misplaced.
Under-sofa toy story [IKEA Hacker]