I am just going to spell this out how it is. People have seen printed in GW rulebooks 25% max characters and 25% lord 25% hero. I think many GW stores will be basing their demonstrations on 25% lord 25% hero. Make of that what you will.
Charging.
Infantry M1-M6 = Basic Movement value + 2D6
Fast Attack M7+ (Cavalry and fliers) = Basic Movement value + 3D6 use 2 highest)
+1CR for charging. -Avian (more likely)
Fliers
Move 10 " and march 20 ". They ignore terrain whilst moving. While fleeing or pursuing, they use their ground movement. (note: the ground movement part may not be entirely correct)
Marching.
Movement distance as normal. When there's an enemy within 8", the unit has to pass a leadership test to march. Not sure how this applies to Dwarfs.
Reforming
Units may reform once, but may neither move nor shoot the same turn. If the unit has a musician, it may move afterwards, or shoot. (Note: I'm pretty sure I'm missing some details on that one.)
Generating Power and Dispel Dice
Power dice aren’t generated by the number of spellcasters. The amount of dice is decided by 2D6. The active player gets the total as power dice and the other player the highest throw as dispel dice (throw 3+5, = 8 PD and 5 DD). (confirmed)
Channeling (confirmed that it exists)
Each wizard may roll a D6 and generate an additional power dice on a roll of 6.
Each enemy wizard may roll a D6 and generate an additional dispel dice on a roll of 6.
You may not channel while fleeing, off the board or when you suffer from stupidity..
Maximum Power and Dispel Dice
The maximum number of power or dispel dice you may have at any time is 12. This includes any power/dispel dice generated by special rules, spells and/or magic items.
Casting Spells
To cast a spell, roll 1 to 6 Power dice and add your caster's power level. EG: A Slann casts fireball and uses 2D6. He rolls a 3 and a 4 - score of 7. He than adds his Power Level of 4, which results in a total roll of 11.
Miscasting
Here is where I think we need a lot more information.
It is rumoured that miscasts are entirely gone, but are replaced by a combined irresistible force/ miscast table effectively:
When you roll a double 6 the spell is cast with irresistible force, but the Caster has to roll on the "lost control" chart, which is devastating, and far more worse than the current miscast table.
Lost Control Chart
Roll of 1: This has been confirmed as being even worse than number 4… Which (pure speculation) may involve every model in the unit taking a hit, this was something I actually heard a while back, but it could be worse than this.
Roll of 4: The wizard is sucked into the warp and the large template is centred over him. S10 hits for something (could be the centre model, meaning S5 for the rest?).
Bound spells
Bound spells are cast like normal spells now, but instead of your caster's power level, you add the level of the magic item. (Not 100 % sure on this one)
Salvo Fire
A rumour I heard a while back was that units with bows (see above), could fire with more than just 2 ranks. What I am being told now is that regardless of the width of the unit, a unit with bows may shoot with an additional half a rank behind the 2nd. I.e. 12 models wide, 3 ranks (36 models). 12 front rank, 12 2nd rank, 6 3rd rank = 30 shots.
True Line of sight
Units draw true line of sight. You are considered in cover when shot at through another unit, granting a -1 or -2 penalty on to hit rolls. Note that someone else has said this is more likely as well.
These look to be some very sweeping changes to the rules. I have only played a little bit of the current edition of Fantasy and I just really didn't care for it - the imbalance in armies just made it no fun. I think these rules changes - ESPECIALLY the % based unit selection - will go a long way to bringing the power level back in line between all the armies. Also with the rumors of every army getting a document updating it for this edition we shouldn't see any weird rules discrepencies like we currently have in Warhammer 40k (two versions of the same equipment, rules and war gear that don't do anything.)