I did not know that, and I just tried now http://www.youtube.com/watch?v=kuyFuWyGu9s and I set the max bitrate quality to 50 when I was exporting and I still did not get that good quality that he did. I smell something fishy....or maybe I dont. Oh well I dont care anymore.
Most of the clips were recorded in 720p with forced AA, some were lower some were higher, you can tell on the clips with the black borders.
I used fraps to record all the clips, edited them, then exported them using a high bitrate and mp4/h.264.
Youtube seems to respond better to h.264 clips, than any other codec. There are many tutorials on exporting high quality video to youtube, just google a bit.
Thanks for all the comments and feedback, I'll be making more Blockland videos in the future hopefully.
Edit: most of the original clips were actually higher quality, but had to be cropped to prevent gui elements from overtaking the screen.