App stores on PCs...Macs...Linux

Following the announcement of the upcoming OSX app store, it's reported that Microsoft is (supposedly) working on a Windows app store, too. Hang on - isn't this what we do with Ubuntu? One of the things that delayed my buy-in to the iPad was the whole walled-garden of the thing - without jailbreaking (with it's attendant consequences) I'm committed to only obtaining and running software available through the App Store.  Now, I eventually concluded that the iPad, like the iPod Touch, is actually a consumer device rather than a computer per se, and I can see why Apple have gone down that route. And I've found the iPad to be an impressive device fr many of my day to day work (and entertainment) activities. Regarding the proposal of an "App Store" for Mac OSX, I was rather relaxed.  After all Linux distros have really had this kind of facility for years - in the form of the repository system used by whatever packaging system used.  In Ubuntu I either access this via the command line or via Synaptic.  There is of course the "Ubuntu Software Centre", which seems to me moving from just a listing of free software to also offering commercial software. In that sense, moving to an App Store model for distributing software for computers isn't particularly innovative, unless it becomes the only way to install software.  It appears that the OSX app store is to be incorporated in next year's OSX 10.7 and added to the current OSX 10.6 pretty soon (Mac OS X 10.7 "Lion" - Sneak Peek). I'm a little uneasy about this move: I don't want to work in a completely closed software ecosystem, and I'm not getting a sense of whether this will be the exclusive mode of software installation. I guess this will be resolved quite soon, as it's coming to OS X 10.6 in the coming months. Update:  Ars Technica's review of yesterday's Apple media shindig (Mac OS X 10.7 Lion: "Mac OS X meets the iPad") quotes Steve Jobs as saying that the Mac App Store won't be the only place to get applications—just "the best place." So that's OK -  for now...