Well here is what I'm thinking:
D200 with 50mm 1.8 Groupings, wedding party etc
D300 with 105mm 2.8 Closeups, Hands & rings, Cake, eating cake etc.
D300 with 18-200 Candid shots at reception, outdoor BBQ type gathering.
I'll have my SB-800 for fill flash as needed. But this pretty much will...