Confirming that old patcher method no longer works. AO will re-download the new one on startup, replacing the old patcher. Sadly, AO is still unplayable using Crossover.
Edit:
I thought I would list what I had tried so my comment here does not seem baseless. I am on a mac, running snow leopard, and my AO client is version 18.1 (the most recent full download as far as I know).
First, as stated before, the old patcher trick has been rendered obsolete by the fact the client checks for the patcher on start up, and will replace it with a new one before you even reach the log in screen.
Second, to install AO you create a windows XP bottle (once again, as far as I know) which makes you unable to install IE6 into it by any traditional method. Winetricks may be able to circumvent this, but in order to run winetricks on mac you need darwinports or macports. Unfortunately, to run either of those you need Apple's Xcode 3, and in order to obtain that by any legal method I know, you must be a registered apple developer, which would seem to eliminate a majority of average users.
Third, just for thoroughness' sake, I attempted the awesomium dll trick, but at 18.1, you have no original dll for you to replace, rendering this method not applicable for those getting the original download.
Finally, as noted above, manual patching is spotty at best and usually just stops in the middle of the process if it starts at all.
I hope these comments help those who might have a better perspective and more experience with both crossover and macs.
-A former windows user.