There is a lot of thought and technique to making a video go viral, but the #1 element still seems to be luck. Here's my hypothesis.... once a cat forum or someone with a large network of e.Friends of cats sees this, the snow ball will get bigger.
The search engines still haven't picked it up. The metatags on YouTube itself aren't linking this as a "related video" to anything yet.
Liza Trainer is doing stuff like this and she comments on other semi-related popular vids with links to hers to drive traffic to them... it's working for her pretty well, so cross-linking is another tactic to pursue.