Similar to what was done on Stack Overflow, I would like the threshold for creating new tags to be increased on Meta.
I'm proposing a new threshold of 1,000 reputation (from the current 99) -- this is negotiable with Jeff, of course.
The proposed threshold is currently 226 users, which should be more than enough people to manage the change
New tags on Meta should be even more rare than on SO -- chances are if a user is having a problem with a certain feature, there's already going to be a tag in the system for that; or, an experienced user will be able to create a proper tag the first time
This effectively prevents tag pollution from off-topic posts by new/inexperienced users (this example and this example each generated 2 new tags)