To expand on that, there seem to be a few misconceptions up here about how Linux things are done (which makes sense, since this is MSDN; people ought to be more familiar with the MS way).
- Linux distros typically provide "package management" for a whole range of applications that are not developed by the distributors themselves. This means they provide installers, up-to-date patches (frequently to the extent that they patch unpatched/unmaintained applications, which conceivably can lead to a sort of mini fork, as Pablo said), testing, and dependency management (the latter being a bit more important in the Linux world, perhaps, but it does cut down on what I've heard called "DLL hell" on Windows).
- Distros--the reliable ones, at any rate--put their code through serious testing before shipping it, including backporting patches to avoid forcing upgrades, and so forth. Distros like Debian are renowned for their stability and reliable upgrade paths.
- Packages soon being unmaintained and abandoned shortly after they are released, as one poster above mentioned, is not a problem I am familiar with. In fact, the upgrade path is often *easier* with Linux, insofar as upgrades are free.
- Microsoft has more testing resources than most, if not all, Linux distributors. QA is probably better as a result. However, since (good) Linux distributions manage the whole range of user applications as well as just the OS, they provide a level of QA that Microsoft (at least officially) doesn't, by explicitly working with upstream providors to work out kinks.
I agree that one is not better than the other. But kneejerk reactions bug the hell out of me.