I installed Solaris 10U6 (10/08) inside Parallels 4 (I had been using VirtualBox, but the MSKCC Windows build image is a Parallels virtual disk file, not VirtualBox). Interestingly, the installer becomes more of a 'staller with Parallels' default 512mb allocation -- it just sits there showing a small console window (which by default is offscreen on my system) for longer than I care to wait. With the allocation raised to 1gb, the installer is snappy and works fine.