Product review (5 stars): Exact replacement made by Whirlpool.  Review web for installation tips first!
I purchased from Amazon, not another supplier on Amazon.  The part I got from Amazon was the genuine Whirlpool manufactured part.

It was not obvious how to remove and replace the icemaker.  I found this very helpful video from "PartSelect" showing how to do it at http://www.youtube.com/watch?v=hmCE3oKpEk0

The current Whirlpool 2198597 replacement part has a funnel on the upper right of the icemaker for the water fill that's a half-inch or so taller than the funnel on my old icemaker.  As others have noted, this prevents the icemaker from sliding in easily past the black fill tube in the top of the freezer compartment.  It's not easy to bend the fill tube as needed to get the ice maker in place.  I found a great tip (perhaps in another review) to use a hair dryer to soften the black fill tube.  This helped a lot, especially when the freezer compartment is cold.