All depends what you are using the vehicle for. Keep in mind that as others have noted, today's low fuel price will only be low until the economy recovers. Today's low price of oil is shutting down exploration, oil sands projects, alternative fuels, etc., many of which could take years to recover. In other words ... once the economy recovers, there is a very high probability that we will be paying MORE for fossil fuels, and the long-term trend is only upward.
Still ... Weekend plaything, not too high annual mileage, maybe the fuel consumption doesn't matter so much. Buy whatever you like, and now is indeed a good time to buy. (Tip for ya, though: Hang in there another month or two until you see the new Camaro. It might change your mind.)
But for something for a long commute and long trips in the summer, etc., I personally have taken the stand that every vehicle I buy for this purpose must use no more fuel than the vehicle it replaces ... and I'm at about 5.5 L/100 km now (diesel VW Jetta).