The bug I described in this EAP thread: http://devnet.jetbrains.net/thread/429816?tstart=0 has returned. Using the 6.1 RTM I tried to move a couple of XAML files from one project to another and the refactor dialog sits at "30 of 505" for "Validating usages of symbols" and just starts running up the devenv.exe memory footprint. I cancelled it at about 900MB as you can see here: (another time I stopped it at about 1.2GB)
Doing a "Collect Garbage" does not release this memory either, I have to restart Visual Studio. I can do some more performance snapshots if you wish, but I suspect it'll be the same as the other 2 or 3 I submitted during the EAP.