Boy, there is no shortage of commentaries/summaries on the PISA results from yesterday, and you can find a bunch of good resources at The Best Posts & Articles On 2012 PISA Test Results.
After wading though a bunch of them, here are what I believe to be the five best ones (though they all don’t necessarily agree with one another):
Four lessons on new PISA scores — Ravitch is from The Washington Post.
10 things teachers need to know about the Pisa results is from The Guardian.
7 Reasons I Don’t Care About the PISA Results is by Rick Hess at Education Week.
The PISA Puzzle is by Dana Goldstein.