I don't think that'll work -- it's "going the wrong way" if that makes sense. You need a DVI to ADC converter, not an ADC to DVI converter.
The new Apple 15" display is an ADC display. The card you need to purchase is going to have a DVI port, so you need a converter that'll take that DVI signal and convert it to ADC.
The adapter you saw on the Apple store page takes an ADC signal and converts it to DVI. If you tried to use that with the setup you're wanting, you'll quickly find that the connectors on the ends of the adapter are the opposite of what you need (there'll be a male connector where you need a female, and a female where you need a male.).
Hope that helps (and is accurate!)