Certainly the addition of this location service would be advantageous (and iirc, Nokia said they would be adding this in the future), but I can't see it realistically making any significant difference to the lock speed.

To elaborate, I assume that obtaining the wifi looking data is as fast as obtaining the cell triangulation, and I can't see the two being too difference. Also, my understanding is that the AGPS assistance data (at least that provided to the N810), took the form of almanac plus ephemerides for the location in question, but the granularity of the ephemerides is something >=50miles iirc, so any gain in accuracy from the wifi location service (assuming there are enough APs to actually make it more accurate than the cell tower method) would make no odds.