I was pleasantly surprised by skype and chrome, who actually provide rpms and debs. Nice!
Open Office gave me a tarball with a myriad of debs. Not the nicest kind of packaging.
Unfortunately the distributions performs their own packaging of a lot of these applications which may give some people the idea that they should use the version packaged by the distribution. The distributions should really stop doing this and refer people to the official packages instead. Otherwise users will be stuck on old versions.
I also don't know how well this kind of delivery mechanism works with automatic updates. Do the external packages get updated in the same way as the packages delivered by the distribution or does anything like Sparkle exist for Linux?