Yes, you can.
See this StackOverflow answer: http://stackoverflow.com/questions/3969484/can-i-produce-a-commercial-application-using-visual-studio-express-2010
There was an FAQ for the 2008 edition with a line that explicitly said that yes, you can. It's hard to dig up anything conclusive for 2010, but Microsoft actively goes around encouraging developers to download Express edition and sell their applications developed with it.
The reason that Visual Studio Professional and up cost money is because they offer features like plugin support, project management, and testing tools. Their primary customers are large companies with complicated development environments. They couldn't care less about indie developers using their compiler and IntelliSense without paying.
To get rid of the "Evaluation Only", you need to register your copy.