There are far better Flash animated shows out there...
Look at The Mr. Men Show.
That's incredibly fluid stuff right there. I wish they got Renegade Studios instead of 9 Story.
Heck, that thing about Ponies has some straight up fluid Flash animation. Even the first Flash cartoon, Mucha Lucha had more fluidity than this. But it's not terrible. Just... I think PBS gave them the squeeze job do to lack of funding. If they had Arthur Merchandising that went back into the TV show, they could have kept the overseas outsourced stuff a little longer.
Sigh... Really. It's been on 16 years, and there's no merchandising anymore except for Gluten free baked good mixes and Annies Macaroni and Cheese (which is actually VERY good. Much better than Kraft's stuff).