I would wait, even if the mpc is less, because:
1) I can. I can afford my gas bills now, and in the "forseeable" future. Barring some catastrophic event.
2) I want a nicer looking car than the current Volt and the opportunity to drive gas free. I do not have a 40 mpc commandment.
3) I want our future cars to be inspiring in a design and experience and I will do all I can to support that view. Lord knows, we need something to get us out of the house, isolated from cellphones, and away from computers.
Caveat: I will only buy a GM EREV so, come on Pontiac, don't let me down!