This is an excellent question. I dislike using numbers because they change rapidly, but I believe that for pieces larger than 10 centimetres that NORAD tracks right now, there are 9,800 pieces. Don't quote me on the number, but the idea is that it's a large number.
Now, space is large; that doesn't mean it's crowded up there, but this is a large number.
There is a recognition that this is an issue by all spacefaring nations. For example, on the RADARSAT constellation that was just approved in Budget 2010, it is our responsibility as a country of this world to ensure that when that satellite system is finished, we can basically dismantle it, bring it back to Earth, and let it burn up in the atmosphere.