The management at my company have been doing interviews to fill a few positions, I'm curious to know how the interviews are going, is it rude to ask one of the management about this?
The answer depends on the corporate culture in your company and the manager you ask. In many companies most managers will be happy that one of their charges is taking an interest in the issues they are dealing with instead of 'only coming to them when you need something handled'.
Some managers however will feel that you're sticking your nose in business that doesn't concern you.
Personally, I would try to find one of the people from management in a more or less informal setting (at the coffee machine, after regular working hours, something like that) and ask the question at that time. I'd say the risk of receiving a bad response is very low and the potential goodwill you gain from showing interest outweighs the possibility that you may annoy someone for a brief moment.
As HLGEM points out, you should keep in mind that they cannot share the specifics of the candidates for confidentiality reasons. At most you'll get a cursory "We have some promising candidates for position A but position B is proving harder to fill".