I don't know of any, other than this forum and news.yc. There used to be Academic Hacker News at http://www.cs.toronto.edu/~ad/news/, but that in effect failed. I'm not that active here, though, so there could be some I'm not aware of.
Thanks for this, even though I haven't used it yet. I've been using the ArcLite online demo (http://jonathan.tang.name/files/arclite/index.html), but it hasn't been maintained; its creator, nostrademons, hasn't been very active; and it is so slow that the fizz-buzz problem fails to run on it.
It might be nice if the download page said the release date of the current file, so that people could compare their copy's date to it rather than having to search pg's comments.