[ Jim Walczak -- About.com ] For a Hybrid vehicle to be able to handle the challenges of off road driving, it must be a “Full Hybrid”. Being a Full Hybrid means that it can be powered by the gasoline engine working alone, the electric motor by itself, or by both working together.
Even though some Full Hybrids have four-wheel-drive, they’re not really designed to go off road. These 4WD vehicles are, in fact, sending power to the front wheels, but there’s still some slippage, so you’re not getting the kind of 4X4 you’d want to run over the Rubicon Trail.

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Finally, while many people do tow trailers and cars behind different types of Hybrid vehicles, even Full Hybrids are not officially “rated for towing”, therefore, they are not suitable for towing trailers over long distances.
According to Greg Wilson, who has his eye on the future of Hybrid trucks, alternative powertrains for trucks (including fuel cells, gas-electric Hybrids and diesel-electric hybrids) are only a few years away, but only Hybrid vehicles with an integrated starter generator have any real potential to match the hauling and towing performance of traditional big block engines.
According to J.D. Power and Associates, U.S. consumers are expected to purchase approximately 350,000 Hybrid vehicles annually by the year 2008. Further, more than one-half of those Hybrid vehicles will likely be trucks! Trucks should account for about 35% of Hybrid sales by 2005 and 64% of Hybrid sales by 2008.
In fact, initial expectations were for 500,000 Hybrid vehicles in production by 2008, however many of the manufacturers started changing their tune on Hybrids and chose to delay the release of some Hybrid vehicle models or even drop some models from their Hybrid program altogether. Many of the auto manufacturers decided to adopt a wait-and-see approach instead of busting out of the door full-force.
Therefore, while Hybrid vehicles are the hot topic in the automotive world these days, and consumers are becoming more and more intrigued by Hybrid vehicles, the fact remains that they will still represent only about 1% of the market by 2005 and 2% by 2008.
Hybrid SUVs and pickup trucks serve as rolling advertisements for better auto technology and less pollution. The question remains, will there be enough of them on the road to be making the statement? Will consumers buy into Hybrid vehicles? The (near) future will tell…

Source: About.com