There are a couple ideas, you can rotate the toys to keep them interested. Check out this article Michelle wrote after Christmas. Here! Or in my case we decided to go through and see what we could toss or donate. Everything else is getting organized.
The other day while picking my son up from daycare I noticed their bin organization. They put a picture of the type of toy with the bin to keep like items together. Although I'd seen this before I never really thought about doing it at home. So yesterday we tried it. So far so good.
Just organize your bins/boxes/whatever you've got by like items. Take a photo. I drug the photo's to MS PowerPoint and added text labels. I'm sure just a picture would suffice as well.