If this means more focus on crafting raids, cool. I really lost interest in ICC after a few months of "stand here to spread damage, move left to right everytime x happens, etc" tanking. I've tanked everything except the Lich King, and can't say anything was challenging to me as a tank. Really seemed like healers were the only people being challenged, but a healer is more qualified to say that than me.
Honestly Halls of Reflection and Pit of Saron are more challenging than anything I've done in ICC.
I prefer 10 mans as well, but I've had lots of fun with 25 man groups. The 25 man ICC runs we did consisted of our guild and some others, so I had been playing with nearly everyone in the group for 1-3 years. I've been in some successful 25 man raids where I didn't know many people, and those could be quite annoying. Lots of dps dick measuring, loot drama, shockingly bad decisions, etc