The below months are being widely reported now around the internet as the latest release schedule dates - I cannot determine the original source and therefore cannot vouch for the accuracy.
Please Check my GW News thread for more a few more details. Or my Vampire Counts and Daemon Hordes threads for race specific info.
March - Vampire Counts
April - Birthday releases
May - Daemons
June - Mordor
July - 5th Edition rulebook
August -Dark Elves
September - 5th Edition Box set
October - Space Marines
November - Mortal Chaos