The title is true. Apple has been shipping 802.11n capable devices that have that ability locked at shipment. In order to unlock it, you have two options: 1) Buy the Airport Extreme Base Station that includes the unlocking enabler or, 2) If you want to use a wireless base station from another vendor, Apple will charge you $4.99 for the software enabler.
That seems like an odd thing to do. Charging such a nominal fee would seem to annoy more users than the revenue it brings in would be worth to the company. Apple’s explanation is that this is a side effect of the Sarbanes-Oxley Act. Supposedly they cannot give away a unadvertised new feature of an already sold product without accounting for it in the typical onerous manner that government regulations require. Otherwise they would have realized the full gain of the product, including the new feature, at the time they sold it.
This makes my head hurt. Let’s just say this would be an unintended byproduct of the legislation. I am not sure if anyone else has ever done anything similar, but I guess $5 to make their life simpler is not the end of the world.