I have a lot of experience of job interviews -- both experience of sitting on interview panels and of being interviewed myself -- and they always strike me as distinctly weighted in favour of the employer.
Clearly, interviews provide an opportunity for employers to decide whether or not a candidate is to their liking and whether or not they want to hire that person. But I'm also of the opinion that interviews should provide an opportunity for candidates to find out whether or not a hiring company is to their liking (and careers advisers and the like will certainly tell candidates that they should treat interviews as such).
Of course, you can often get a pretty good idea of whether you want to work for a company from the interview. However, it seems to me that it is nearly always the company, rather than the candidate, who retains the power in this situation. For starters, the company will be interviewing several candidates, not just the one--and in this climate you can bet your bottom dollar that there will be more than one candidate who the company considers 'appointable'. Secondly, interviewers (and others) may encourage candidates to ask questions, but in my experience certain types of question are often not welcome. At interviews, I make a point of asking the questions 'What's it like to work here? What's the culture like?' in an attempt to understand what the people are like and whether the company would be a congenial place to work. Yet these questions often meet with looks of surprise or indirect, meaningless answers. They are simple enough questions and my sense is that (many) employers simply don't like being asked such things. It is, however, considered perfectly acceptable for an interview panel to ask a candidate very similar questions. 'What are your three strongest and your three weakest points?' is a good example.
And then you come to the business of informing candidates of the panel's decision after the interviews. The successful candidate is informed very quickly, of course, but those who are unsuccessful can wait several weeks before being informed, and then this is usually via a standard email from the HR team with no opportunity given to seek feedback. I can't imagine that it would go down too well if a successful candidate kept a company in suspense, taking several weeks to respond to their offer of employment!
When I sit on an interview panel, I do my best to answer candidates' questions as openly and honestly as I can. I also let unsuccessful candidates know the outcome quickly myself, ahead of the impersonal email from the HR team. Not only is this the decent way to treat people who have taken the time and trouble to attend for interview, but it also gives the company the reputation for being decent and honest.
It's just a shame more employers don't seem to see things the same way.