This is from Thomas Hickey's blog. He is chief scientest at OCLC.
"The idea is to have a Wiki that complements WorldCat. People could add reviews, cover art, comments, etc. and relate these to bibliographic records (maybe at the FRBR work-level too). We hope the system is flexible enough so that people do (good) things we're not expecting. We'd like the Wiki to be available anywhere WorldCat records are"
Read the full entry here