Our sister site Big Download has the PC patch files for patch 3.1.1 mirrored. The download is only 8 megs in size, so it shouldn't take you too long at all if you download it from them. However while the Blizzard downloader is working now, you might not have much luck later on. The Blizzard downloader has been known to crumble under intense usage (I know it's counter intuitive given the Blizzard downloader works off torrents, but it's what happens).
Big Download will be getting the Mac patch up soon enough, and we'll update this post when they have it.
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