Since my Shaman has been 80 for a couple weeks now and has made sufficient progress I've had more time to devote to leveling my Death Knight. He hit level 74 last night and just starting the Dragon Blight. Which is to say that is wonderful. I'm thrilled that the dual starter zones allow someone to run through both and make terrific progress before ever really getting anywhere in Northrend. 74 already and at the very beginning of the third zone, so I would expect to at least be nearly level 76 by the time I complete it. And that is if I do not run any instances with him before then.
He also hit 450 herbalism last night, so my impression that there were simply less herbs to go around than mines was mistaken. I think that must have been a by-product of the number of players herbing in the zones earlier and my Gatherer not working properly. I've since updated Gatherer and reimported the data pack, but it's still not showing the nodes I myself haven't collected. Together they must have given me a false impression. I know it's rough, but I would really recommend that players continue to herb in the outlands until you at least get to 425-430. Since no one is herbing in Netherstorm or Shadowmoon Valley any longer, its nothing short of easy to do now. Plus you can fly while doing it. Once you hit that 425-430 level you can move into Northrend and should have no issues picking any herbs you come across in the starter zones.
Meanwhile I've been farming away on my Shaman and at last accumulated all the mats I needed for a Titansteel Destroyer for my Death Knight. He can't of course use it yet, but I have it now and leveling away like mad so that he soon can.
I still haven't witnessed any appreciable changes in how I have to deal with mobs from the earlier levels. Mobs generally die within the first rotation (IT > PS > HS > HS > DC/DC) and I largely ignore the issue with runic power dump. If I pull multiple mobs or if I'm fighting an elite I'll pop DRW and DnD, but otherwise I don't even monitor my runic power level. Its simply not needed. Which of course is to say that even with mostly green quest items now the class is still fairly powerful. It wasn't just the outstanding blue starter gear.