I think people are thinking 10mans will be "easier" than the 25 mans much as they are now. However, they are only easier because you are doing it in your 25 man gear while 10 mans are tuned for people who only have access to 10man gear.
With putting 10 and 25 on the same tier, 10 mans will have to be tuned for the same level of gear just fewer people. ie NOT easier or harder
Throw what you know raiding to be right now out the window and start fresh
Cataclysm =/= Wrath of the Lich King