For anyone who doesn't know all the rumours can be found here:
http://www.warseer.com/forums/showthread.php?t=253845If these are true looks like horde armies are going to love it:
stepping up
stubborn if you have more ranks then your opponent
horde rule, if you are 10+ wide all can fight in the front rank and you also get an extra rank of fighting as well
Magic is also changing a lot and looks like spells will have a weak and powerful version of each other.
Fear and terror now only give CR, no auto-break
The one that is going to be a pain is the new % system for building armies. 25% for chars which is good and bad. It means no Slann and EOTG at 2000 but at least you will be fielding more troops which is always fun.