Some time ago users' accept rate has been removed from their flair. I can understand the rationale behind this decision (even if I disagree), so I won't discuss it here.
From my point of view, this has made a problem even more evident. Many users (more because no one tells them they have to accept some answer) will forget to do it (or they just don't care) and they'll ask questions again and again (I don't want to talk about reasons for this behavior).
Accepted answers are an important part of Stack Overflow (both to help future visitors with the same problem find the right answer, and to encourage newbies to answer a question).
What I suggest is to strongly encourage OPs to accept answers. Let's say that a user with a too small accept rate (but with a high number of questions) can't ask more questions. I would consider a delay as warning (wait 30 seconds before you can post your question if you're near that threshold).
Why this? Because accepted answers are an important part of Stack Overflow: they help future readers to quickly find what works (votes are often not enough). They help who is looking for open questions to skip them. They give an extra compensation (not right word, I know) for whom answered.
If accepted answer is an old concept (and down/up votes are more important) then I think it should be dropped (or its name changed to something more meaningful). Of course I think it shouldn't so users must be educated to use it.