We did this breakfast last year (September 2006.) We had an 8:00 a.m. seating (I think the first of the day) so that we could hit the park at opening with plenty of time.
We had a great time! The characters (Pluto, Minnie Mouse, Daisy Duck, Lilo & Stitch) were dressed in Hawaiian wear and flowers, and seemed to give every table lots of attention. The kids loved it!
There was a table near us with a couple perhaps in their late 20s, no kids. The woman was dressed in an outfit similar to Minnie's polka-dot dress, complete with Mickey ears. I think there also was a table of young adult Japanese girls, and I noticed the characters gave just as much attention to these tables as to the ones with children.
The food was also very good, we thought. They offered standard breakfast fare (scrambled eggs, omelets to order, bacon, sausage, toast) as well as some special Hawaiian/Asian fare (I don't remember real well, but rice, I think salmon, pineapple scones, pineapple preserves, fresh tropical fruit.)