Dunno, the script is searching for html5+love once it's started. Unless Twitter's search api is a performance hog there shouldn't be much of a problem :)

Although I like them, I see no point in using alternative webkit-based browsers like Stainless or Shiira. I'd definitely give Chrome a try, though - their extra efforts really make it worth!

Performance improvements could come from i.e. unsupported and thus unvirtualized eye-candy DirectX features which would have a negative impact on performance under normal circumstances. Anyway, afaik all the mentioned games have OpenGL renderers, but I assume that you use the stanard DirectX renderer in World of Warcraft.

On the other hand, performance drawbacks because of wine's virtualization are very small but naturally they do exist. Adding an extra layer of wrapping takes time. Of course, maybe wine's handling of win32-specific calls and systems is more efficient than Microsoft's implementation in their operating systems ;-)