As 2010 draws to a close, GreenBiz asked executives from a range of companies -- all of whom have been featured in the news this year -- to tell us about the most exciting green prospects, challenges and changes they anticipate for 2011, and what they think 2011 will look like from the perspective of 2012.

Here's what they told us when we asked:

What do you see as the biggest potential challenge for your company in 2011?

Rob Bernard, Chief Environmental Strategist, Microsoft

For Microsoft, our biggest challenge is raising awareness among technology leaders and decision-makers (CIOs and tech purchasers for example) on the challenges presented by energy constraints. Currently, when I look across the industry, I see IT professionals who are not focused on energy; they see it as a mid-term problem rather than near term. There's a train coming down the track regarding energy consumption. Right now, they don't see it and they aren't worried, but they should be.

Joseph Danko, Director of Sustainable Solutions, CH2M HILL

The economy. We expect continued slow economic recovery and this will impact our rate of business growth.

Michael Meehan, Chief Technology Officer, Co-Founder ENXSuite

The good thing about the cleantech market is that there are a vast number of opportunities and various segments of the market are still quite nascent. Navigating opportunities sounds like a "champagne problem" but it's not as easy as it sounds -- all companies in this space will continue to evolve their go to market and place their bets on the most promising opportunities. Placing the right bets on opportunities in cleantech is the biggest challenge for all companies.

Eric A. Spiegel, President and CEO, Siemens Corporation

It's pretty clear that we're not going to do much in terms of any kind of global or even federal carbon legislation.  And so the challenge is going to be how do you keep the momentum going for an environmental portfolio in an environment where the federal legislation probably isn't going to help much? My prediction is you're going to see a lot driven by cities and states.

Suzanne Shelton, Founder, President and CE, Shelton Group

Though we're seeing many companies settling into true sustainability commitments, we're still seeing a lot of resource constraint. There's been a trend for a while for corporations to name a VP of sustainability, give that person an FTE or two and then no actual budget to do anything meaningful with -- from conducting an LCA to building a true brand platform around sustainability.  As long as that continues it will be tough for the folks who actually have a terrific sustainability story to tell to actually tell it, and, as an ad agency exclusively focused in the sustainability space, tough for us to help our clients tell it.

Michel Gelobter, Chief Green Officer, Hara

Keeping up with demand for our solution and all you can do with it -- a good challenge to have! Faced with the radical visibility/transparency on energy and resource use that our software creates, our customers will be demanding help with data-driven innovation in energy use, capital and operating expense optimization, and value creation.

Kevin Surace, Chairman and CEO, Serious Materials

Initial cost of retrofits for customers.