I had a serious situation the other day, after installing SMupdater and everything was working smooth, I installed using Metamorph from the market a Theme built by a trusted person and after the install of said Theme, my Droid didn't like it.
First it continued to give me error messages and than restart itself, it did this about three times in a row and than the Droid just went black, than the long bootup screen, which continued the loop over and over again. By than I was thinking of ways to get a replacement
Finally when I was about done and panicking I remembered about the Recovery Procedure "Power Button & X on the physical keyboard" it wasn't until that step did my Droid began to act right.
So, I said all that to say, unless there is a Theme made by Sholes I wont be putting any themes on my Droid, just a tad bit to risky for me.