Congratulations on the new release. It will be awhile before our custom apps catch up due to the level of changes and missing hook points where our app needs them. I am looking forward to when I can upgrade.
It's definitely a bold vision, and I can see it being very useful. It'll give me a great excuse to do spring cleaning.
We can set the tag page's image, title, and description when we define the tag?
I'm excited for the new release. I think achievements will help my site so long as we can get our third party app integrated easily. It sounds like it shouldn't be too crazy to do that.