Did you just migrate to SubVersion? I did and I'm not looking back. However, most of on-line collaboration sites for projects (like SourceForge and even Tigris) doesn't support SubVersion repositories yet. Of course, you can host your own (as I do) but wouldn't it be nice that your project has CVS checkout ability also?
I thought about that also (especially since my WebPac project has CVS repository on SourceForge). After searching for such a tool, I found blog from Tollef Fog Heen which has a nice tool, but a little to basic for my need.
So, I started hacking. And created sledgehammer (in Tollef's own words) tool for this task: svn2cvs. It's on the way to FreshMeat as I write this...