To the OP - I would usually respond to this post as such:
"Tough luck. Deal with it. Learn to play your class again. Yad duh da Yad duh da."
However, I am, for the most part, in complete agreement with you. Tanks got used in this update. I am pretty much useless right now as I stand on the middle ground of level 30. I will give you an example of my first run through with the update.
I was strolling through Antonica at lvl 29 near the Oracle Tower, mining away. I was running my usual route when I harvest there: Griff to Oracle Tower, scrounge around, run to Winstalker Village and then hit the scarecrow fields and back. For quite a few levels now, I have not worried about aggro. On my way to WV, I saw that I was getting hit by a granitescale basilisk. HUH?! I turned towards my assailant to find that he was green! Sweet! I am going to like this change! I dispatched him with no effort at all and I enjoyed the increased casting time on my new spells. Seeing as how I was right by the Ruins of Caltorsis and knowing lvl 21 was not gray anymore, I checked to see if the Advisor was up. Low and behold, he was. Chest drop for sure, right? WRONG!! I proceeded to get torn asunder by a level 21 mob. And for those not quick on the uptake, that is 8 levels below me. So I ran away, rebuffed, and tried again. Not much better. This time, I actually died. I chalked it up to the fact that they revamped the nameds. Good for them! They should be a lot harder.
Well, later the night I went into TS. I knew the Dead River Basin was no longer going to be a safe haven. I ran down the river as I usually do and stopped near two grouped lvl 21's. They were camping the drowned troopers and were scared of the now Heroic lvl 25 Skeletal Protectors. So, I took one on to see if I could kill him. No problem. I dispatched him and his add without breaking a sweat. The change only affected the named heroics, I thought. With this in mind, and feeling like a good samaritan, I went after a lvl 23 Heroic ++ Drowned Lieutenant. 30 seconds later, I had turned tail and ran, though I did come back with Skeletal Rage and a hex doll and beat him pretty well. This is the part of the update that I don't like.
IMHO, they changed too many of the mobs to be grouped mobs. I think this is what the OP meant. I don't have a problem with the fact that a group tagged mob can kill me. I do have a problem when every single griffon in the griffon fields is now a group mob and most of the Skellies in the Basin are too. That takes away from solo play. If you look hard enough, though, you will be able to find your regular mobs tucked behind that scary group mob.
All in all, I like the changes. I like the dueling and I like the fact that my skills do some major damage now. SOE did a good job, even though they did mess up my class a tad bit.
Have fun everyone!