I have 3 toy poodles. they're the greatest.
I've read that poodles are all one breed of dog, but they have been divided into different sizes, and breed true to them. the original was the large one, the Standard, which was a water retriever from Germany. the poodle is actually a German dog, the word "poodle" comes from a German word that I'm going to mis-spell, "pudlen", which means "to splash".
anyway, some people decided that such a lovely breed might be bred into something a bit smaller, so the smallest dogs were bred to the smallest dogs until they had a "true" version of todays Miniature poodle. it measures 12-15" at the shoulder, whereas a Standard is 18+. after the miniature was granted official status, of course, the next thing to do was breed smaller still. this may or may not be true: it's alledged that some other toy breeds were involved in getting down to the current size for a toy now, and it has also been granted seperate status.
T-cups are not recognized, and don't breed true. my own dogs all had t-cups for daddies, about 3 1/2 lbs, and my dogs are 8, 9, and 11lbs respectively. the biggest one just barely misses being a miniature. their mothers were also tiny, in the area of about 6lbs.
breed standard for show calls for a solid colour coat, and specific styles of hair cuts, except for breeding dogs/bitches and puppies. show poodles may also be exhibited in corded coats, but they are rare. (one of my dogs is corded-anyone else have one-I'd love to compare notes) paris are becoming quite popular now as pets, but only as pets, and a particular coat pattern called, "phantom" is highly sought after by a breeder I know.