Archos clearly doesn't have the resources to compete with the likes of Apple in the tablet space. Opening up the Archos Android tablet is a good move by them, as it clearly differentiates them from the locked-down iPad.
I noticed that as well as providing the Ångström linux image, they have also published the API to use their proprietary media app (music, vids, photos and - take note Apple - Flash) from within Android.
I really hope that the "opening up" strategy works out for Archos. Given their somewhat dubious history of in-house support (or lack of it) let's hope the community can make the most of this.
By the by, with the latest 1.6 Donut firmware the Archos 5IT is actually pretty stable and functional, and with this announcement it's got the potential to be a geek's favourite toy over the iPad hands down.