Seriously – I’m getting the spinning beachball sometimes for two minutes. Often it’s 15 seconds or more…
Perhaps a bit more detail would be helpful, at least which DTP(O) and OS versions you’re running? 
Running 10.6 on a Macbook Air (1.6 GHz), DT Pro Office 2 (beta 6). I should be clear I’m talking about moving files between databases, as introduced in the most recent update.
DTPO does seem a tad more sluggish in the 2 days I have SL installed.
How many contents/groups did you move?
FWIW, I tried to move about a thousand items (2GB) from one database to another (splitting a database) with DTPO 2.0pb6 and it sat for an hour and a half. It seems that it hung. The first 15-30 minutes it was grinding the disk and using the CPU and then just sat there.
I could try to reproduce this if needed. It does not seem to have happened on smaller data sets, although it’s possible there was a single document in there that was causing problems. I ended up moving the files by exporting them and reimporting them.
Move seems to work fine with small sets (~10-20 records).
Likely would have been faster doing that by duplicating the original database (e.g. with Finder) and remove unwanted content from each copy. 
I’m not talking about anything near as big as that. I find even if I move a dozen files between databases, it can take 20 seconds or more. There’s just no zip to it, and it’s a major deterrent to using the feature.
How large are your databases? E.g. I can move hundreds of text documents within a few seconds. And could you check if there’s any free memory available (see Apple’s Activity Monitor)? Thanks.
Since it hung, probably definitely. From a file access perspective, it should be quicker to rename files from one place to another (ie, no need to copy and delete everything in a 10GB database, or even just the 2GB move). It would still need to update indexes in both.
FWIW, my databases are primarily filled with largish PDFs. Some up to 100MB. That info might be useful when considering different use cases (ala the survey which went around a little while ago).
Just bought a MacBook Pro (I had an MB Air before). Problem is no longer a problem.