To get all the features of Nikon's CLS you need a SB600 or SB800. I think the SB80DX will only work in maunal mode but I'm not sure. I once owned a SB80DX when I had the D100 and I can tell you that the SB800 is a much better flash.
Hedley Originally from Merthyr Tydfil, Wales -- now in Arkansas
Go to Nikonusa.com site to find compatibility chart. It's not the most userfriendly site. if you can't navigate to (hatre to admit, but I did it yesterday, couldn't do it today!) then chose Photohelp and ask.
Unfortunately you'll need a new flash. I had an 80DX when my D200 arrived and it just doesn't work well, it won't even pick up ISO or aperture. Basically you're left with a manual flash that will trigger from the camera but thats it.
I had the same debate myself, also moving from the D100/SB-80DX to the D200. I found the Useful Links page on this forum really helpful. Specifically, the link to Nikon Speedlight compatibility and features told me everything I needed to know.
As you indicated, I also decided to go with the SB-800 and never looked back.