Hi,
I have successfully installed PokerStars through CrossOver for Mac, using the WinXP bottle (also installs with Win2000 bottle).
I have been playing multiple tables for the past hour just fine. You cannot manually resize each window, but the "cascade" & "tile" options work. My MBP 15" fits 2 games open at once side-by-side easily.
The only other issue I can see is that your opponets info doesn't show up when you hold the cursor over their head. This info includes their location (town/city) and their chip count (which you can see during play anyway).
PokerStars also runs very efficiently through CrossOver. On my Core 2 Duo 2.33GHz w/ 2GB RAM, it's currently using a total of between 4% to 12% CPU load and ~90MB RAM. Very responsive.