Reading the Two Headed Giant FAQ, found here: http://www.wizards.com/default.asp?x=dci/doccenter/home , it states that Vintage THG is a possible format.

This could have interesting effects on decks. For example, one head plays control while the other head races for a combo win. Both heads could overwhelm with beatdown of some sort. Both heads could race for combos. The permutaions are fascinating. Decks could be tuned to new levels of single-mindedness when they don't have to worry about defense.

The first idea that sprang to mind was one head running Dragon without disruption while the other head plays mono blue without a win condition. But, because the decks are treated as being the same deck, there's no downside to building this way.

I know that I will attempt to organize quite a few VTHG tournaments to see how Vintage evolves in its new format.

Here's the scenario:

I have Akroma in play and Sakashima in my graveyard. I play Reanimate targeting Sakashima. It resolves, and I bring Sakashima into play copying Akroma.

How much life will I lose? Four? Eight? Fourty-two?