Imo, there should be something even harder than heroic on the dungeons. they're often lolzor and done. New difficulity should be like a ton more hp and much harder swings, almost like a raid.I went in HoR with a Kingslayer tank and healer. the tank rushed through whole HoL to Volkhan (including general Bjarngrim or whatever) and never fell below 50 % hp. When that happends, it's time for something more challenging that still doesn't require at least 9 peeps
i agree heroic 5-mans are 2 easy i think that blizz needs to step up the difficulty for (heroic) good players or just drop heroic difficulty for some of the earlier Northrend instances so good players dont have to w8 a long time for instances if they get something easy (like cot cos or nexus or something else that doesn't give very good loot for lvl 80) . (i may be wrong but doesn't leaving a dungeon early give you a debuff or like a CD on the random dungeon finder).