Thanks for asking, I'll tell you what any Linux distro could do to increase functionality and popularity.
For now Ill just focus on Ubuntu for the simple reason it is the most popular. I agree with what others have said about Ubuntu essentially skipping a release cycle to focus on fixing all the bugs reported in their very own forums. Also I do believe they should advertise some more. What about something like Google adsense? Free for anyone to use because it's FREE. If people want their distro to be on their website or blog then all they have to do is copy in a code and it will fetch the ad for them. Simple.
That distro will be tailored made for sparking curiosity about Ubuntu and such. Imagine seeing ads like these:
Ubuntu - The REAL virus thwarting OS
Ubuntu - Open Source never looked so good.
(this one's a video)
A person is collecting old computers that are too slow, so he/she brings them all to their house. Then installs Ubuntu on each one and slaps a *new* sticker on them. Next you see a family crowding around their new computer, learning how it works. While the person goes back to collecting the old computers.
I figure with as many ad capable people who support Linux as there are, this could definitely catch on.