We are reevaluating this based on community feedback. The new heuristic to prevent questions being asked will probably be based on a combination of question closes, question deletes, question flags, and lack of significant upvoting, even at very low levels (0.20 etc) -- scoped to new-ish users.
Based on the discussion at
We decided to go in a different direction. This is the new proposal.
After your first 10 questions, it will require 100 more reputation to ask every additional 10 questions. If you do not meet this reputation level, you will be unable to ask any more questions.
Bounties you have started will not be checked in step 1, so you can safely start a bounty without losing the ability to ask more questions.
If the users' historical questions did not meet the required reputation bar at the time they were asked, they will be anonymized and ownership from those questions removed. Yes, we will be rewriting history. (existing answers to those questions will not be affected in any way)
The net effect of this change is that we want to prevent people from asking dozens, hundreds, or thousands of mediocre questions (that is, they don't get upvoted). You will need to ask questions that get a modicum of upvotes -- or earn rep in some other way by answering questions or editing.
Examples of users who'll be affected initially on Stack Overflow
It can be difficult to grasp the effects of a change like this without taking a look at the sorts of users - and questions - it will touch. So here are a few users, arbitrarily picked from the thousands who would be blocked from asking further questions on Stack Overflow: