On a good note, it looks like the drop in radio utilization translated to a significant throughput increase. On some of our APs, we are seeing a 100% increase in throughput speeds. This was using a 2.4Ghz N client with 20MHz channels connecting to an 1140 AP. I'm going to do a site-survey later on some of our 3500 APs.
I also temporarily disabled the 5.5 and 11 Mb speeds and saw another slight (20-30%) jump in throughput, but we aren't ready to kick 802.11b clients off the network.