the 2008 brochure I'm looking at shows the breakfast & lunch are also 2 table service experiences--they're listed in the "character" column, but all 3 meals list "2" as the symbol for what type of meal this is, and that means they charge your 2 TS. Sorry!
http://www.disneydining.info/diningplan08.pdf
While they may call the dinner "signature" I think that's just because it's not exactly a character meal, although there are some characters there, but it's more of a brief show. The dinner includes the meet & greet & photo with Cinderella. During the meal, the mousemaids Susie & Perla do circulate to the tables for pictures, then the Fairy Godmother comes out for a little song & dance show (about 10 min.) all about Happy Celebrations (she acknowledges birthdays, anniversaries, etc. but not by name) She does not hang around for pictures. So you get a little character bit (and direct interaction before dinner with Cinderella...very nice photo packet in presentation folder comes with cost of meal)
We liked dinner, May 2008, (a party of 4 adults) because we felt the menu was more to our liking and closer to being worth the cost. We had the BLT salad, prime rib & chocolate buckle for dessert. Like it all. One in our party had the salmon with crab soup starter-he liked it; one had the tortellini-said that was good, but not great.
We were mainly going for the experience of eating in the castle, and did not expect the food to be fantastic. The food was good enough, but the castle is awesome.
Wouldn't do breakfast or lunch, as adults only. The thought of being in there with a kazillion little kids trying to get princess's attention did not appeal to us.)