I use Beatport streaming to build sets, then buy the actual mp3s to gig and record with when I've got it figured. I'd love to one-click replace the streaming songs on a playlist with mp3s and keep my cues and comments.
Does anyone else do the same? Let me know why this couldn't be done?
Or take it a step further: integrate and collaborate with Beatport and do a Buy button in Traktor. There's revenue there for both I bet :)