Ok, so Alansa and I will be trying this out tomorrow in preparation for the London Tourney in two weeks time. Some questions:-
1) What are the victory conditions and objectives? It sounds as though this is a straight points count, but with the attacker starting out at 2/3 the size of the defender, while the initial defending formations count double their value.
Should the 'Defender' get anything for exiting troops successfully on the other side of the table?
2) Clumped concealment markers might be a problem as you suggest. Perhaps the 'spotter' should get an additional +1 where flags are within 15cm of each other? Also if two flags are intermingled (within 5cm), a 'reveal' will spot both formations
3) How do unconcealed formations work in the scenario; eg artillery? While it must be placed 'out of sight' of the road, does it's presence automatically permit the defender to move 'off-road'? Do A/c and teleports also work in the same way?
4) Can 'concealed' formations perform assaults, or are they purely restricted to OW firing?
5) How should 'Concealed' Eldar initiatives work given that they can have different values?
6) How would a space bombardment be carried out on 'concealed' formation? (eg the defender has a spaceship and plots a bombardment that covers a flag - - -)
7) Presumably, The attacker can designate air and space reserves?

Presumably, if there are no revealed attacking formations on the table, any defensive air formations get stood down in turn #1, following which the attacker may then pounce?