It's a product announcement by Knuth, for a successor to TeX.

Telling any more would spoil the fun-- and if the sentence above doesn't sound like big fun to you, well, then don't even bother with the link, you're not in the target audience.

Really, it's a video, not everyone wants to watch a video.

Can I assume it's a joke product rather than a real product?

Yes, it's a joke product. It's 34 minutes, and rather funny, but not likely something you'd take time out of your day to watch in it's entirety.

Different strokes, I guess. I take 34 minutes out of my day to watch a Knuth video every chance I get.