I just got an email from blizzard stating that they are going to release a client for Linux users in July of this year.
This message is going out to a select group of our subscribers only. In the coming days, the announcement will go public, but this is just for you guys for now.
On July 1, we will be releasing a Linux-based client for playing World of Warcraft. The problems we've seen in the past with using the Windows client on various things like WINE and Cedega and recent pressure from our customers have led us to conclude that a Linux client is something we need to make happen. It will not be open source, but there will be .rpms, .debs, and an installation script made available.