Jay Pipes recently wrote about a problem in mysql, which basically is, that prepared statements do not use query cache, which results in not-as-good-as-it-could-be performance. You should read the details yourself here: Minding My P’s and Q’s (Prepared Statements and Query Cache Episode 3).
Essential part of the message is, that he looks for volunteers to help resolving the situation. If you feel like you can help â€” drop him a note. thanks.