Wogrim
Smash Lord
The big reason to upscale to 1280x720 for YouTube "HD" was so that you'd get the bigger screen (480 pixels tall, which is the height you're capturing at if you want good quality; the regular window is only 360 tall last I checked). However, I have just noticed that as of just now, you can also get the bigger screen with just "HQ" vids. Please note that adding "&fmt=18" to your links marks it as HQ, but DOES NOT give you the much-desired bigger screen (that may change of course).
Whether or not you get better video quality (because of YouTube's conversion to flv) if you still resize it remains to be seen; I'll post some vids here resized and nonresized for comparison when I get around to it, and invite anyone else interested in maximizing YouTube quality to do the same. Please don't post old HQ vids, because the hope is that they've changed the HQ conversion to fit the new size (old ones are at normal size, so they're just stretched onto the bigger screen).
Whether or not you get better video quality (because of YouTube's conversion to flv) if you still resize it remains to be seen; I'll post some vids here resized and nonresized for comparison when I get around to it, and invite anyone else interested in maximizing YouTube quality to do the same. Please don't post old HQ vids, because the hope is that they've changed the HQ conversion to fit the new size (old ones are at normal size, so they're just stretched onto the bigger screen).