My colleague at Locus, Rich Horton, is a far more productive soul than I. In addition to all of the many things he does, Rich writes ‘year in review’ overviews for most of the major magazines in the field each year. He’s just started posting them to his newsgroup, and so far he’s written about Asimov’s, Analog, and F&SF.
For what it’s worth, I found myself agreeing with Rich about Asimov’s, especially his comments about the novella length fiction, not quite as sure about F&SF (I think it had a very good year, but not quite as good as Rich did), and less convinced about Analog. Actually, to clarify about F&SF, I thought that Sci Fiction was the best magazine in the field in 2004, but I would say that F&SF was the best print magazine in the field.