Neither have I, but I think its still much too soon to reuse the word. I think it'll be a few more years yet before people disassociate burn with writing to optical media.
Further, burning a disc has certain internal logic to it: Oh, the laser changes the medium's colour (like a sun burn, or a fire). This use of burn for a torrent doesn't really make sense to me. Why not grind or chop? (as in make a bunch of little pieces). Or maybe dice... this opens the door for silly puns quite nicely too.