It's no surprise: when gas prices go up in the US, sales of fuel-efficient cars also go up. March 2005 now holds the record for sales of hybrid passenger vehicles in the United States: 16,619 cars sold, a significant gain over the previous record month, December 2004, which saw 10,441 sales. Of the March hybrid numbers, 10,236 were Priuses., but all hybrid car manufacturers saw gains and record sales. Green Car Congress has some great graphics illustrating just much of a jump this really was.
With summer approaching, it's unlikely that gas prices will drop substantially, and there's good reason to suspect they'll go up more. Demand for hybrid cars is, in turn, also likely to increase. But Priuses are already hard to come by, with waiting lists in most locations. Although Toyota has already boosted production, Honda and Ford (with the Hybrid Escape) may be in better positions to take advantage of the demand. MixedPower.com reprints an article observing that the Honda Accord Hybrid's high price is a way of controlling demand; it is also could end up being a source of big money for Honda if those turned away from Toyota car lots decide to go with the Prius' main hybrid rivals.
This is why GM & DaimlerChrysler (among others) are kicking themselves about not jumping on the hybrid trend, and focusing on trucks/SUVs now, fuel cells later. Not because they feel a sudden urge for responsibility. Because not having an attractive higher-mileage vehicle out now is putting them at financial risk.
