So according to Psypokes, only Isshu-native Pokes are obtainable Pre-National Dex. Which means that this is the first time in the main line of games (RBY(FRLG)/GSC(HGSS)/RSE/DPPt) that Pokemon like Pikachu won't be available in the Regional Dex.
Folks, if this is true, then we're about to break the "600 different species of Pokemon" mark.
uh. we've been talking about that for like the last 10 posts?