I'm signing the petition - but it's not going to help.
Blizzard have said many times that they have no plan to support Linux. Instead, they contribute to making their games work well with Cedega and they always release Mac clients... in fact, they do the best job of Mac games out there imho.
World of Warcraft works really well with Cedega and this has reaffirmed Blizzard's position on Linux.
So it really doesn't matter how many people sign the petition - you won't see a native version of the game... unless there's a Blizzard in hell

But you can bet it will work very well with Cedega.