Not to beat a dead horse, but they've been promising that feature for Versions at least since July 2008 (that's as far back as I could trace in their Google Groups mailing list). If you're happy with Kaleidoscope's current feature set and will continue to be happy if they never deliver on this promise of future updates, go ahead and buy a license (it does look pretty nice as-is). Just don't hold your breath waiting for that merge feature.