OK, so I compiled RDesktop for Panther's X11. I use Microsoft's RDC dialy to do my Pocket PC development.
FIrst impression...its a LOT faster. And I mean a LOT. As in scrolling in the dev environments are at least 4-5 times faster. Just moving windows around, etc... are dramatically faster.
Its also remapping keys and not really stable for me yet. I'll experiment with it more...perhaps it needs a different setting.
But if rdesktop can be that much faster to the same Windows XP machine...I wonder if it can be improved even more to work natively under OS X.