Feature Request: Better Tag Management

I've been having a tough time both navigating and choosing tags.  Can someone give me an idea of what the plan is for tags?

If it's not already in the works, I'd like to suggest replacing the existing mutli-select box interface with a multi-value autocomplete field.

This will probably be a less popular fix, not sure, but I'd like to suggest usage weighting of tags  as well as the addition of a "tag cloud" (interface that lists tags in alphabetical order but changes the displayed size of the tag based on usage weight) for both choosing tags when posting and navigating tagged content.  The idea is the most popular tags would rise to the top and the less popular one's would sink to the bottom.

As an alternative to the above idea, maybe allowing groups to setup their own tags (maybe picking from the global list) to make the number of tags smaller and easier to navigate/choose.