I didn't spot this; I heard it over at the SO forums.
That's right: there's a Region 1 (US, Canada)
3-disc Collector's Edition of Hot Fuzz slated for release Nov. 27.
Edgar himself has confirmed that it has nothing to do with double-dipping, at least on his part; he never wanted R1 to get only a single-disc version and he was unhappy with the way the Walmart set (which wasn't his doing) was handled. So he's making sure the 3-disc has even more extras, with an extended Fuzzball Rally, more video blogs, and a fifth commentary with unnamed guest. (In a way, commentaries 2-4 are also extras for R1, since the Walmart set didn't have them.)
Hopefully we'll get more details soon!