To have the best chance of running Guild Wars 2 in CrossOver, you must download this special build here:
http://www.codeweavers.com/xfer/GW2Test/
(enter 'guildwars' when prompted in order to download).
If you are on a Mac with NVIDIA graphics hardware, you are quite likely to experience graphics problems which will make the game unplayable. Users of ATI cards may also experience serious graphics problems.
If you are on an ATI Mac and experience poor performance, you can try tweaking the
HKEY_CURRENT_USER\Software\Wine\Direct3D\FixedVShaderLimit registry key to something lower than 275. For many users, however, this will result in graphics bugs.
Note: you will see reference to a need to pass '-dx9single' to the installer, reference to downloading 'Gw2.exe' instead of 'Gw2Setup.exe', and reference to setting various registry keys throughout the forums. You may disregard these with the latest build, posted around 5:00 p.m. on August 29, 2012. This should recognize a CD installer, should work with the Gw2Setup.exe file, should not need the -dx9single parameter, and should set all the likely needed registry settings for you. (Updated linux registry settings may be forthcoming - I've got a Mac, and there may be things a linux box needs that aren't automatic). The Gem Store should work, also.
Please give your feedback in our forums - we want to know how things are going for people who try.
Please, Please!! try before you buy. Guild Wars 2 is still unsupported and, as noted, is likely to run poorly on many systems. If it does run for you, tell us!
Thank you, and good luck.