"OMG iLevel"... I've always known about the concept of ilevel but long ago in vanilla and burning crusade, we went by another method of judging upgrades... KNOW YOUR CLASS. I am proud to use gearscore to low standards and rule out the people with shitty gear for whatever I'm doing, but serious raids also go by inspection or armory.
Very torn, yet another "Is blizzard a genious, or an idiot?" moment with implementation. If 10==25 then they need to make some big perks to 25. 2-3 drops in 10man, 6-8 drops in 25? 10g per person in 10, 50g per person in 25? 3 badges in 10, 9 badges in 25?
Stuff like this is what can keep 25 raids alive and healthy. Just because it's the same loot does not mean there are no perks to raiding in larger groups. If you sit there saying "omg this emblem item is perfectly designed for my class, I need 200 to get it" your going to want to get it as soon as possible. Regarding difficulty and the fact that 10mans are easier to build, teach, and are generally more forgiving (and that's not a theory).. well we'll have to see for ourselves, I know a lot of people currently take for granted 10 man raids because everyone inside walks around with better quality gear.
What this WILL bring about is the death of 20,000 random pug groups. "NO, I won't go to your raid because I have a guild run." "NO, I'm saved!".