What wil be the next trend in the us stock market?

Biotechnology, probably.

I predict the area of Green Energy will gather some steam, but not to become a trend, as the logistics aren't there, its not sexy, not very hypeable, and it's got a lackluster name. Already many new bio-refinerys are not being built, and the true cost of producing biofuel is more HYPE not reality, more than it's worth. All the rest are sucking gas, So the new trend has to be outside the norm. The Area of most concern is the economy, Jobs, food costs, etc. So the next great trend has to be: Diversified Areas that include: Revival of American Know how.
New American 'Business, which is: ( Production, Jobs, new Technology, Oil and Gas Wells, Gold & silver mines, Water electrolis for Hydrogen fuel production.) New technology.

Green energy is already starting to bubble. How much of it will ever pay out however ...

I'm still highly sceptical about food-crop based biofuel. I was raised on a dairy farm and I know what damage corn can do to soil after only 5 years of cropping.

Hardware - microdevices, smart devices, new interfacing technologies, combined technologies and possibly light- and/or quantum- based computing. If the last two prove feasible.

Other - community based utilities and workspaces. We're already seeing it with city gardens, "slow-food" meal-preparation meetings, and Bunnings warehouse here in Australia holds workshop nights where you can use their workspace to build projects. As populations move to high-rise living, there will be demand for places and space to actually do things. Not to mention the social benefits.

Precious metals

Commodity bubble driven by inflation and weakening US Dollar

Water

Seems like most of us think Healthcare is going to be big...

Just copying what Google is investing in.... or try to invest in.

I have more faith in Education than in green energy. We will still rely on Oil for another 30-40 years. There probably won't be any break-thru in the next while.