I'm using Wine.
Well, I would say solely the white "Launcher" that's started by Gw2.exe in "Program Files/Guild Wars 2/" is having the memory leak so far. The installer that's downloaded only puts a few files in Program Files and then automatically runs Gw2.exe in "Program Files/Guild Wars 2/", starting the white "Launcher" to download the game. So the white "Launcher" is having the memory leak, and preventing it from showing seems to prevent at least that memory leak.
According to the Wine AppDB bug submission above, there will also be a texture unloading problem that will cause a second, different memory leak, unfortunately. I'll have to see about that another day.