That folder is 5gb on my Air, at 300-400mb per video.

I have a category selected that says it's 22 possible videos, and out of those only 18 are currently cached on my machine. It looks like that directory is kept pruned at least occasionally.

Nonetheless, just an indication of the potential size on disk would keep users aware when they pick these screensavers. An explicit "Screensaver videos" category in the disk usage graph is also a good solution.

I mean, how else did you expect it to play a random assortment of high quality videos as a screen saver? It's good these aren't bundled, and very few people have metered internet.