• Addresses separated from orders.
  Totally agree, it will be more user friendly and will bring more possibilities about workfow and conditions, I hope it will not break the actual user database and it will be possible to import actual customer database in the new system.
• VAT support in core.
  Totally agree, as an european seller, VAT is the things that bring me the most difficulties to configure, If some advices for an european seller is needed, don't hesitate to ask me.
• Allow folks to switch to multi-page checkout.
  It could be a cool feature, but I'm afraid that it would make the creation of checkout related module extremly complicated and will bring a lot of bugs or will bring a lot of code, just for that things. If you make a magic hook that automatically manage all things, why not . But for me it's not a critical issue (true core discount possibilities module would be prior to me)
• Separate validation from submission for checkout panes
  Not sure to understand about that, I thrust you ^^
• Actual store administration theme
  Not sure to understand too, if it's to retheme administration, why not, but I already find it very good.
• Better support for internationalization, including core VAT support.
  Totally agree, internationalization is a credo of drupal 6, it should be a credo of ubercart
• Remove uc_notify.module and replace it with conditional actions.
  Totally agree, with workflow, drupal 6 actions etc.... there is enough possibilities to manage notification in a more powerfull way than the ubercart notify module
• Fix cart pane API Smiling
  Agree
• Separate Views integration out into its own module.
  Agree, I would add to bring some efforts about it. Like adding more fields (especially attributes related, more arguments, more all ^^). I say that for 2 reasons :
  • Actually, the catalog module is good for a people that quickly want a catalog in the oscommerce style. If you want something more extensible, more easy to maintain, you will use views, and the ubercart views integration is too light today.
  • Views will come into core with 7.x version of drupal, working on a great views integration will save some work later ^^

  For that reasons, I think it's more logic to bring efforts in a really good and complete views integration and let catalog module beeing a third party module that bringing a catalog module into core and make core views integration anecdotic.

• Get the rest of the manufacturer trappings out of core
  For sure
• Try to get rid of any other module_exists checks, too.
  Don't know what's the problem with it, maybe performance issue... I thrust you ^^
• Move Store Links block out of core and into a contrib module.
  Yes, good idea
• Invoice templates should be overridden at the theme level, not in the module dir
  Totally agree, and I would generalize for all module as you said. I would love to see some .tpl.php files to overide checkout page/panes pages etc...
• Update stock support.
  Totally agree, it is a critical need for most shop, and the Cpill module is not maintained anymore, I would see more possibilities for the core stock module
• Review line items API.
  Agree agree agree, it still need some work for about performances and bug
• Core conditionals system
  Not sure to understand, does it mean the end of workflow ? Will you replace it by the core drupal 6 action and trigger module ? Or will you adapt Ubercart 2 to the new rule module (that is the next workflow-ng) ?
• Simpletest for full unit test coverage.
  Don't know how simpletest work, it seems good ^^

I would add some personal questions for next releases :

• Do you plan to continue support for catalog module ? I know it is pretty out of the box for a simple shop, but I can be easily replaced by some others modules like views, taxonomy list, taxonomy image...
• Do you plan to add more reports on the reports module, if yes, but if you are out of ideas of what could it be added, I have a lot of commercial and marketing people that work with me, and I can ask them what they would see