The biggest problem I'll have with my CommunityServer to DotNetNuke Conversion

So the biggest headache I'm going to have with my conversion from CommunityServer to DotNetNuke is going to be how I get DNN to accept or handle the old CommunityServer URLs. Why do I need to do this? Because Google, and all of the other Search Engines out there eat this site for lunch, they love all the content on here, and if I don't provide direct replacements for each URL I'll take a HUGE hit in referrals from the search engines, which will directly effect revenue generation from the Adsense here.

I need to pick a few brains tomorrow to figure out how I'm going to do this.