tanks got seriously buffed
DPS got seriously buffed
healers got buffed
all bosses do less damage and many have less HP

I've 2 manned heroics since patch 3.0 and some people have 5 manned Kara, I ran a 30 minute FULL CLEAR of ZA earlier today (we had 31 minutes left on timer when 4th boss went down, lol). Its just the time to have fun and do instances you might not have done before, everything is pretty easy now. Only 3 more weeks till wotlk.