Who is Darby anyway?

My son loves, loves, loves the characters from Winnie the Pooh. He knows all of them on sight and has for quite some time. His favorite is Piglet. He has a little stuffed Piglet that he has had since birth that is his transitional object. Seriously, my son loves him. I have had to sew him back together at least 3 times! He is so dirty, and once upon a time he had stripes and squeeked. No more of either one, the stripes can only be seen in old pictures and the squeek, it is a distant memory.
D-Man is not really into television, he doesn't know who Barney is or who Dora or Diego are. (I like it and plan to keep it that way.) But he loves his Pooh characters.

So we DVR the show, "My Friends Tigger and Pooh." It is on the Disney channel and he will watch those and laugh and laugh and ask for more "Tiggpooh." I even starting enjoying them, but it lead me to ask the obvious questions, if you have ever seen the show. Who is Darby and where the heck is Christopher Robin? It seems that the 100 acre wood must have had a little too much testosterone so they added a little girl to make it more appealing to females? Personally I don't like Darby, she is a know-it-all and doesn't really do it for me. D-Man, well he doesn't care as long as Piglet, Tigger (he calls him Rarrr) and Pooh are there. I guess that is what really matters. Little kids don't care that Christopher Robin has been replaced by an annoying little girl named Darby, why should I?