1a) Yes, there are zones that will curb stomp yo azz. It's not like your beloved Oblivion is before hacking it, the zones don't level with you. ;)
2) Also, remember that Actiblizzard made leveling through the old content easier by design. They want you to get into the new stuff just as bad as Johnny wants to get there. :) That means that there is probably some mob nerfing going on, but as you advance levels the challenges will come. Again, jump into the random dungeon queue. This will make you a member of a team of 5 that have their different roles and you will (usually) be required to be (somewhat) at the top of your game. As you level up, the dungeons become trickier as well. Dungeons, FTW!
3) I should be on tonight... anyone else? :)