Check out MacCentral ... apparently, Arlo Rose has confirmed that the current version of Kaleidoscope will be the last. Here's the pertinent quote from his Website:
The last version of Kaleidoscope we released was 2.3.1. While we still support it, and encourage people running pre-Mac OS X machines to download and register it, we are no longer actively working on a version for Mac OS X.
Kinda figured ... the few remarks I read from Greg on the subject didn't reveal much enthusiasm for keeping it going. So where exactly does that leave the state of UI enhancement for OS X?