I decided to take a look at the new line up and here are my overall thoughts.
On a positive note, I was impressed by the reduction in preservatives in their ingredients list. It's gotten a lot better. The high fibre version is also significantly higher in fibre. About 3 grams more than the regular one. It also doesn't seem to be a significant source of fat in any of the three cases, though I think that would be vary depending on how you prepared it (Eg/ what % milk you used or if you added butter)
On the down side, they are all still loaded with salt. Looking at the vegetable one specifically, you really aren't getting a whole lot of veggies from this product. Maybe 1-2 tbsp cauliflower...tops...and that's me being generous. It also robs children of the opportunity to be exposed to these vegetables, grow familiar with them and actually start liking them. This is not a substitute for veggies by any means.
Nutrient wise, there also isn't a significant difference between the new SMART brand and the original. The omega 3 is certainly present in the omega 3 version, but I don't think it makes up for the salt and lack of other nutrients.
Overall the only really great thing about this new Kraft Dinner is that the higher fibre one is significantly higher in fibre (though much of it is inulin which many researchers believe is not as beneficial as other fibres) and the decrease in preservatives. Other then that, it's still KD and I don't believe it should be making up a significant amount of any child or adult's diet.