I've been drinking in every detail about DND4 in anticipation of getting the books in a couple of weeks. Of course, it appears that several places have slipped on the ship date. (And a few people seem to have OCR'd PDFs, judging by the formatting of their posts.)
If you want the spoiler-riffic information, check out these forum threads:
http://www.enworld.org/showthread.php?t=227714http://www.enworld.org/showthread.php?t=227705http://forum.rpg.net/showthread.php?t=396755 (Also posting this so I can check up on these later. ~_^ Got up to pages 28, 16, and 39.)