If there is more consumer interest in the EA bundles than in the standalone Motion Plus units, I am sure Nintendo will make more available. I doubt they are out to dick EA over and only have WSR bundles when that game launches. They will have Red Steel 2 bundles out after WSR afterall.
Of course Nintendo did not simply "give" EA the units and let EA pocket an extra $10 in profit from the titles which retail for $60. EA will, I assume, actually take a bit of a hit on profit per title, and Nintendo will take a hit on profit per WM+, but they both need to do it because their products need each other. I am sure that the size of a WM+ and a game boxed seperately is bigger than when packaged together though, so they do get to cut the distributor and the retailler out a little bit anyways.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.
