The youngest our kids have gone is 3, but I found meeting characters at meals to be much better for the little ones. The situation was much more controlled-- no pushing, no bigger kids (and sometimes adults) cutting in front of them. We had issues with this even at Mickey's Toontown Fair, and while the buddy castmembers handle it if they see it, it made both of our kids very upset.
If you're not pressed for cash and can justify spending whatever it costs now for the breakfast, I'd go for it. We did the Princess breakfast a week or so after it started, and it was great. If my kids (now 11, 7, and 2) didn't love Pooh so much, we'd do it again. Our 11 year old dd is "over" princesses, and is trying to brainwash the baby not to like them, either- only Belle and Mulan are acceptable to our big girl.
Julie