This month we began reporting sales of a new hybrid model: the Lexus LS 600hL. Lexus began shipping the 600hL to dealers in July, and sold 267 in August. While Lexus’ new flagship hybrid has generated some buzz, it shouldn’t have a major impact on monthly hybrid numbers: future 600hL sales volumes will be modest, between 150-200 units per month.

The LS 600hL is the first of several new entries we can expect in the hybrid market this fall. Another is the redesigned Toyota Highlander Hybrid, which will begin appearing in dealerships in October. This month, Highlander Hybrid sales slowed dramatically as Toyota moved its remaining inventory of 2007s. Expect low sales for the Highlander Hybrid again next month, followed by a jump in shipments in October as the new model arrives.

Following the Highlander’s introduction is the Chevrolet Malibu Hybrid, which is scheduled to ship to dealers in November. Pricing for the Malibu Hybrid, which uses the same mild-hybrid belt-alternator-starter system as the Saturn Aura Green Line, begins at $22,790, roughly the same as the Aura hybrid. While the appearance of the new Malibu has been improved considerably, it remains to be seen whether it will be more popular than the Aura Green Line, which is on-track to sell just 1500 units this year. The Malibu may also face stiff competition from the Prius, which has a base price that is $1800 lower and a combined fuel economy rating that is 70% higher than the Chevy.

Finally, in December the Chevrolet Tahoe and GMC Yukon Hybrids arrive in dealerships. These two full-size SUVs will be the first vehicles to use the two-mode hybrid powertrain developed jointly by BMW, General Motors, and DaimlerChrysler. Pricing and fuel economy ratings have not yet been announced, but GM says we can expect roughly a 25% boost in gas mileage, putting combined fuel economy at roughly 21 MPG. While the Tahoe and Yukon hybrids won’t appeal to many traditional hybrid buyers, they have the potential to extend hybrid technology into households that previously have not considered a hybrid vehicle.