According to this Apple knowledge-base article:
Your approximate location is determined using information from local Wi-Fi networks....
Which I would read as a "no" (that's not the end of the sentence, but it doesn't mention anything about other hardware).
You could leave some feedback requesting that this be in a future release. As far as I can tell, the API wouldn't need to change for them to add more devices – much like it can use other devices in iOS. (Whether they'd be likely to do this, of course, I have no idea.)
Of course, one could certainly write software to gather location data and provide it as a service to one's own apps. But I'm guessing you want it to be used within the CoreLocation
framework (a.k.a. "location services"), which would pretty much require Apple to support it – or some extensive hacking.
1Yeah, my hope was to allow for the use of a USB GPS device for applications that made use of the Core Location API to give them a more precise position. Looks like my only hope is to either hack together some kind of dependency injection, hope someone else does, or wait to see if Apple ever decides to integrate a GPS chipset on their non-iOS products. – Wilco – 2012-04-30T17:58:02.383