Hmm... I don't think that would work. Almost all media types require beginning at the start of the file to read media type and properties (codecs, bitrate, resolution, etc) so only the first segment of downloading file could be played at all IF it's a streaming media type... the only exception I can think of here is MP3s, which have bitrate info in every frame. Additionally, for files like AVI, the segment must also be fixed, rebuilding the index telling it how many frames there are and such... I would much rather see developers making the client better in terms of performance, bugfixes, and compatability with other clients (like the BearShare metadata with MP3 hit results problem) than them spending time bloating their software with a built in media fixer/player.