Well, you can't put campy cassettes on a shimano hub, and vice-versa, cause the spline patterns are different. Having said that though, it sometimes is possible to mix and match a non-group cassette with your drivetrain, although performance may not be optimum. For example, you can generally use shimano 9 speed wheels on a campy 10 drivetrain, as the width is not too different. But IME, 10 speed shimano and 10 speed campy don't work very well together, partly because the index mechanism in the levers moves the respective gears just a little differently (Shimano and Campy are off by a few millimeters). But there are people who report having no problems as well with such a set-up so go figure....
Anyway, short answer: take a look at the cassette and see what the mark is (duh!)...if it's campy, don't despair, you can also get a conversion cassette to make it perfectly compatible with your shimano drivetrain.
Although....if it were me, I would have checked that info (hub type) before getting the wheels...