Yeah that's a good point... If it was a preview, then I would make it very low quality. What it is, is recorded footage from fraps (as I'm sure you know they create huge file sizes), then rendered out in Vegas, to reduce the video size. This is them sent to my friend for editing, as he is best at that, then uploaded from his virgin cable connection to youtube. I'm rather jealous of his Internet, although it isn't quite a fibre connection.
That raspberry Pi idea isn't the worst actually! Ever since I saw them come up on Engadget, ive always wanted one to play with. They're not too expensive I don't think either.