Really enjoyed watching this. Ravenholm in 1 Minute, Coast in 45 Seconds etc... It's a segmented speedrun released couple days ago by http://sourceruns.org. Non-scripted.
I can't believe that ABH thing is even possible. The Valve guys tried to fix bhopping without even thinking of the most obvious way to bypass that fix...
Oh well, it looks even more baller now than on older runs.
There is also downloadable version in the youtube video description which includes a commentary track. It is highly recommended.
While the cutscenes are indeed boring and take away the pace, it's not easy task to make all those NPC teleports perfectly. In the commentary Matmo says that he was trying one of the cutscenes over 8 hours before he could make a satisfying run.
Compared to something like Quake done quickest where you can just compile all world record runs into a single run, in this speedrun it's a team effort where everybody continues with the same health, weapons and velocity from the previous segment. And obviously you can not go back, unless you record everything again from that point.
They will also make another commentary which will be really detailed about how everything was made.