This is a really long thread, but I do want to weigh in as a user of ubercart who has had my store up and running for 7 months.

I do not care about a smooth or perfect upgrade path from drupal 5 to drupal 6, and I do not care about perfecting UC v1 for drupal 5 before moving on to a Drupal 6 version.

I would much rather have a UC version for D6 so that I can play with all the new toys at once.

I agree with nekobul. People who have invested time and effort into 5 have what they need. And I do not think you need to take any new features you build in 6 and back port them... I have not touched my site in 7 months. I am going to have to do so much upgrading on so many modules, I will probably just start fresh...and it would be great to do that with D6.

At the end of the day, if I want a new feature, I would much rather have you tell me I need to upgrade, than to have you tell me I need to downgrade.

I knew I was on the bleeding edge when I built my site using UC (as opposed to using a licensed product that was at a release 2.x). I think most users feel that way, and you might feel "artifically" bound to keeping on the D5 track because I know you are good guys trying to do the right thing and don't want to leave anyone hanging...but as for me, bring on the D6 version, and I will do whatever upgrade/rebuild/start from scratch/ process you suggest.

And one more insight...I am already getting pressure from my hosting company to upgrade to D6, as they see D5 as a security risk. If that happens, I have to move hosting companies or start all over with another shopping cart if there is no UC for D6!!! And I don't want to do that!