Like many on the site of the first link, you might not grasp what TM is about: Racing against the clock (your time or others)... It's like multiplayer-hotlapping... And no, it DOES make quite a lot of fun... Just download the demo of TM Original, TM Sunrise or the full TM:Nations, there might even be a number of people online...
These kind of movies have been going on with TrackMania for a while now. The 3K project that was posted earlier was completed in October 2005 (and before that was the 1K project etc.):
The same guy has orchestrated the infamous 10K project but it seems to have been a little too difficult one. Here's the 10K page though: http://trackmania.tntune.com/xK/
With the replay editor and rendered to a video with a fixed framerate, all in-game.
Nope, that's what makes it fun, but it remains being about hotlapping with other people online (I should have added "over loopings and other insane stunts" though, happy now?)...