The Prius NWH20 is more aerodynamic, powerful and efficient than it's predecessor. It has a lighter battery and can operate for longer on electric power. The battery pack for the newer Prius is warrantied for 8 years, although it is expected to last 15.
It has been suggested that because of the popularity of the Prius amongst celebrities that the car is bought more as a statement or fashion accessory rather than as a reaction to increased fuel prices or global warming.
Prices for a Prius obviously vary between dealers and countries. Many countries do provide tax incentives on the purchase of hybrid cars, in the UK most incentives are related to parking fee exemptions. In the U.S tax incentives change as a certain number of cars is sold by the manufacturer.Cost is a relative thing. In Australia you can pay $21 000 for a small to medium sized Toyota Corolla, or roughly $38 000 for the Prius, and NO, unfortunately there are currently no tax incentives.
Hybrids on the whole currently make up only 2.4% of new-vehicle sales in the U.S. but with increasing oil prices (recently hitting the magical US$100 a barrel), and 'green issues' consistently hitting the headlines, the Prius and its stable mates might just start to chip away at the huge market.
A new release Prius is expected to be hitting the market sometime in 2009.