This might be slightly OT, but have you guys experienced the new DASH format in youtube videos? The 720p/1080p videos are now configured with DASH, the video and audio streams come separately, its impossible to download them together, best option is to download them both simultaneously and mux them together with say FFMpeg, now is there any DM that does this automatically? I had so far found only one Firefox extension and one linux command line program that downloads the streams and muxes them automatically, but none of them has the option to speed up download like a manager does, so any takers?
If you want to experience DASH, go and check this video, download the 1080p stream, chose MP4: *www.youtube.com/watch?v=xzCEdSKMkdU
More info: Files from Youtube without sound!!!!!!