With my quote of $2/watt systems, that is referring to utility grade installations, not residential. Obviously this is still an aggressive price point and I hope they achieve it. But it is not too far outside of what we currently have. FirstSolar has achieved Euro-3.25/watt with a more expensive technology. I would expect nanosolar's numbers to be somewhere between $2/watt and Euro-3.25/watt initially, then gradually fall as production ramps up. About the promises you hear for installed price, be careful to read the fine print. You may hear price per watt in utility grade installations, not residential. Obviously utility will always be cheaper than residential because they have economy of scale on their side.
http://www.nrel.gov/docs/fy07osti/42058.pdf
For the moisture/technical concerns sited, nanosolar's products, now currently shipping, carry a 25 year warranty. I think they have managed to lick any technical problems.
http://www.nanosolar.com/products.htm