If the Wii is getting a price drop to $150, then wouldn't that make it the same price as a DSi? DSi XL would be more expensive too. Shouldn't the DS family see a price cut too? (DS Lite-->$99, DSi-->$129, DSi XL--> 149)

That would be logical.

Considering the DS is outselling the 3DS though, I think they don't want to do that.