Oreo has yet to release an official description of the flavor, but judging by the packaging, it's probably safe to assume they're made with the standard chocolate Oreo sandwich cookies filled with a Swedish Fish-flavored creme. Basically, it's as if they stopped just short of jamming hunks of the gummy candy in there, although that probably wouldn't be too bad, right?
Anyway, if you've ever looked at a pile of Swedish Fish and a stack of Oreos and wished they could be fused together into a single snack food, well, that's kind of gross. Also, you should probably look into working at Oreo's Wonder Vault. Cheers to many glasses of bright red milk.