My thoughts..
Stuart Little should not even be considered! First, it's just a live action movie with CGI's pasted on them. Second, it was an awful film. It got horrid reviews, and it Bombed quite quickly. Even the Powerpuff Girl Movie is more diserving (I liked the girls, but it's not oscar worthy.)
Jonah, 8 Crazy Nights, Hey Arnold, and Wild Thornberries are also undeserved...I mean, other than Thornberrys, I have no problems with them, they just don't seem like Oscar material.
Basically, Lilo and Stitch and Spirited Away are the two listed by Disney that deserve consideration (Spirited looks like it could win), but Return to Neverland and Treasure island are only Oscar Worthy, if Oscar means the Grouch, and Oscar Worthy means it's worthy to put in Oscar's can.
Spirit the Stallion looks like another good candidate. Ice Age deserves consideration, but I don't think it would make the cut. I loved it, it's just not quite like Shrek or Monsters Inc, two better films.