One tidbit, though: if the amount of players deciding to stop raiding normal mode, and instead to just to LFR, is greater than the amount of players that didn't raid before and decided to "graduate" from the LFR to the normal modes, Blizzard might be faced with the spiny issue of a decline in the population willing to do Normal modes.

More so because I expect Normal mode to become harder than today. After all, LFR is taking over in tackling the accessibility problem, so Normal does not have to be as accessible as today.

Blizzard might be able to tackle this issue by allowing cross-realm players to form raid groups using it's RealID system; this would make it much easier to find a raiding group. On the other hand, this has the potential to greatly reduce the desirability of realm transfers, as well as to further reduce the "community" feeling from realms; the (almost inexistent) world PvP, normal and hard raids, and the AH seems to be the last remaining things the player really depends on his realm for, the rest can be done in a cross-realm way.