The main thing is that Healers and Tanks don't have anything shiny and new. We get promises about overhauls but without details they feel like pretty empty promises. The argument that we don't need another tank or healer Job is also pretty empty. By that logic they shouldn't add any new Jobs ever cause we don't really need any new dps jobs either. People get more hyped usually for new and shiny over old with a fresh lick of polish particularly when you haven't been shown anything about what the freshly polished old is going to look like.
I think its also naïve to assume that people only enjoy one type of role there will be plenty of people who are happy to play healers (like the main tank in one of my FC's statics) who may be very interested in making the switch to the new shiny. It will balance out in the end but that is likely as much because people willing to play the other classes will filter back because of overcrowding in the dps role.
Which raise another Healer/Tank potential issue. One concern I heard raised yesterday is that for those willing to heal or tank that they are going to feel pressured to have to take those roles because of over population in the dps role making feel like the choice of playing what they want is going to feel undermined. There are people who tank and heal in statics because no one else is willing to rather than that is their ideal choice.
For me personally it just means the new jobs hold little interest for me so I don't feel hyped over them. Apart from that all we have is the setting to go on and I think I need to get a better understanding of what they intend since right now it feels to me like they have shown me the trailer to two separate expansions and I am having trouble connecting them in my mind. As far as the new Jobs go, my main concern is getting nagged by dps in the first month to help them get past long queues. I like helping out but I have limits.