I hate that part of getting new rugs. I do not like carpeting. Anyway, a friend of mine had light carpet installed and when she wore dark clothes, you thought she got a pet. She had a cleaning company come out and clean the carpet. I think she got Sears carpet cleaning. It worked so I guess the steam cleaning or whatever they did got deep down and loosened the last of the fibers. If you think you might have bad carpet, you can try to pull out a loop here and there. If it is easy to pull out of the backing, then I would make a call to the company or store that sold it.
I was talking with a friend of mine last night and she said she got new carpet last month. Her husband used the shopvac a couple of times and it got rid of the fuzz. Shopvacs have stronger suction so maybe it'll work faster.