New Sonic Adventure 2 screenshots from Official Dreamcast Magazine reveal some details on Chao raising. Instead of animals being freed from robots in order to nurture your Chao, you will find odd little rods. Apparently these will be compatible somehow with your virtual pet.
So, where have the animals gone? Don't fret, Sonic Team haven't taken them out of the Chao-raising process - that would be just silly. Instead, Sonic has to whistle (!) near bushes or bins in order to grab the little critters' attentions and pick them up within stages.
The ODM article also shares some information on the new tricks Sonic can perform. The blue blur will now be able to grind on rails (but you knew that) AND swing on bars! Like a true athlete!