This appears to be the RF receiver, not a full GPS engine. The website says:
Broadcom provides a software library that realizes the GPS navigation solution in the host using minimum resources and with no real time requirements.
So, it's RF and maybe DSP hardware, but it leaves it to the host microcontroller to do the heavy lifting. This is probably why the battery dies so fast when I use the GPS on my iPhone.
This sort of solution makes sense if you care less about power consumption or development time than the per-unit production price.
An 8 bit microcontroller like the arduino doesn't have enough horsepower to do the heavy lifting.