Thanks for all your guys's hard work on these two updates. I'm really looking forward to using Drupal 7, and the fact that Ubercart is ready for it will make my transition that much easier.
As for the Drupal 6 - Ubercart 2.3 update. I'm glad to see that another "box" has been enabled for Ubercart. Thickbox is really dated and Lightbox2 was getting too old for me as well. ColourBox is a nice addition (although I like Prettybox).
Also I noticed that the new 2.3 version is roughly 200k larger. I'm not complaining about the size, but this huge difference makes me wary on upgrading my live sites . Why is the new version so much bigger? Surely it can't all be code changes and additions. Was colourbox integrated into the module? Did someone leave some extra crud in the zip?