Firstly RIFT is running pretty well on my Mac (27" iMac 2.93 GHz i7, 16 GB DDR3, ATI HD5750 GPU, OS X 10.6.8). It's running at high resolution full screen at 2560 x 1440 with no display problems or apparent frame rate problems seen so far. Thanks CodeWeavers!
The only issue I see is that occasionally (maybe once or twice a week) I find my character moving in the last direction I sent it and not stopping. So if I've been holding the 'W' key and then release it, the character will continue moving forward, usually right into a bunch of high level mobs or over a cliff, seemingly depending on what is most inconvenient at the time. The only way I've found to stop it is to either log out or to mouse steer my character into an obstacle. The obstacle method seems to work as soon as I manage to hit the barrier. It's almost as if a keyboard buffer is full, but I'm not sure that makes sense here as it seems to happen randomly; I can spend 10 minutes mashing my keyboard in a warfront without problems but then get bugged whilst meandering around doing nothing much.
One thing I figured out on my own. I have a UK keyboard and the hash (#) symbol (needed when writing #show in macros) is usually accessed using Alt 3. This works but only if you use the right Alt key.