I've just started experimenting with the patterns catalogue and the search with pattern feature, and I consider these to be huge game changers in helping people find certain patterns of code easily and make changes - especially the find and replace which allows you to define your own refactorings!!!!.
My biggest concern however, is, will there be an easy way to share patterns between developers, import them, check for patterns against a database online, etc.? It would be ideal in an organization for people to easily all use the same patterns.
I think it would also be neat for all patterns to be grouped or combined into rule sets, (think fxcop - security, performance, design, maintainability, etc...) or at least tagged so that you can focus on choose what you want to focus on at a time.