I'm guessing the raid range is five levels like old ldon was. (or was it seven? heh.) I doubt they remembered to change it. it also has to be a 63+ average.
In reality, unless you are raid-geared, you will die. and since raidgearedpeople are all seventy now - theres an effective required level of 70. assuming time geared level 70s, if you have less than five groups you'll still probably die.
most have death count limits - IE, you lose if your raid has more than 50 combined deaths. so you dont bring along people with crappy gear. this includes monk deaths on pulling, but you cant really not split in some areas, because you'll get your raid raped and then the death count will be even higher.
everything summons, duh =p
mobs run to get help at 50% in some areas. one room in the EF one has like 20 basically impossible to split mobs, that run faster than R5.
with some, you have to keep three bosses within a certain % health of each other or you basically lose.
basically, every single sneaky mechanic that you can think of was in LDoN raids. if you've seen it anywhere else and it was unusual, you'll see it again in ldon. They'd be fun and rewarding, except for the crappy loot and the death limits.