We really, really want to get Übercart 5.x-1.0 up and running first. Once that happens we plan to put (nearly) all of our efforts into Ü 6.x-1.0. There's quite a list of things that will need to be changed and improved to make Übercart compatible with Drupal 6, but we still want to be compatible with Drupal 5. Drupal 5 will be supported up until Drupal 7 gets released, so plenty of people will still want to use it for a while. Übercart needs to be there for them.

Since Drupal 6 and Ãœbercart 1.0 will be coming out around the same time, all the new features that we make for Ãœbercart 2.0 will be for Drupal 6 only. D6 looks to be much better from a developer's standpoint, so we won't want to take a step backwards and write new things for D5. Major bugfix releases will probably still be made for the 5.x version, but only if they are severe enough. I can't say at all how we'll decide that until the time comes.

As for what needs to be changed, just the very basic hooks like menus, database schemas, and forms. You know, 90% of a module's code. This is a checklist of all the things that are updated between 5 and 6. Ryan, Shawn, and I are going to go through each module and compare it to the checklist. I'm thinking it'll be fairly easy, but tedious. I don't know if there are any tools other than the handbook pages, but I'm the kind of guy who'd want to do it myself anyway.