This is a head's up that he's going to bail on the project like he always does. When he quit 0x10c it was because he wanted to work on smaller projects. I guess this WebGL project is not small enough though.

It seems like Notch just likes doing the fun initial work on games but gets bored once he's worked out all of the hard problems. I can hardly blame him for that, most of us are guilty to some degree, but he shouldn't market his projects so strongly if he is just going to ditch them.