Jim Bolla has a list of questions to ask someone you're thinking of working for. Some of them are just kind of warmups to get everyone in the mood, and honestly I would expect the employer to volunteer stuff like "what our organization does" and "how IT helps us do that more effectively" in the little speechy bit at the beginning. But absolutely, if you get to the "do you have any questions" part and you still aren't clear on what the company does, it would be very wise to ask. After that we get into some really good stuff. If you're unfortunate enough to be interviewed by HR you may not be able to push hard on their source control or continuous integration strategy, but you will want to. These are the details that add up to whether you will like the job or not. I know because I come in to mentor these people when they are unhappy and unproductive, and these are the things I end up telling them to change .
Kate