Microsoft Streets & Trips 2009 and also Microsoft MapPoint 2009 will include a new, optional, USB GPS 'Locator' based on new u-Blox 5 technology, Navation GPS 168. Only the Canadian shipments of Streets & Trips will at first include this new u-Blox 5 USB GPS Stick. S&T w/GPS Locator in the USA will, for the time being, include still the USB GPS-500 based on the SiRFstarIII technology. [Edit: The new USB GPS Stick, Navation GPS 168 is now available in USA, too]

As seen on the first picture, this new USB GPS Stick is a very beautifully designed product. It is quite small in comparison to other GPS receivers I have tested. Small size equals convenience, but it also means a compromise in the antenna size. The new u-Blox 5 based receiver is slightly more sensitive to weak GPS satellite signals (by 1 dB) than the good old SiRFstarIII chip, but the antenna of the new USB GPS Stick is most likely a bit smaller. I say "likely", because I don't know it for sure; I would have to break the unit to actually see the internal antenna. Smaller antenna size usually has lower RF gain.
u-Blox 5 USB GPS Stick vs. SiRFstarIII GPS-500
I took both USB GPS receivers for a test drive to downtown Toronto. I went to the area most difficult for GPS receivers. While any GPS unit will usually perform satisfactorily in most places, most GPS units will straggle among tall buildings.
To do the side-by-side comparison, I was running two instances of Streets & Trips, to be able to record two GPS tracks simultaneously. Both GPS receivers were placed on the dashboard, close to each other (a few inches/centimeters apart), close to front window.
As shown on the above screen shot, both receivers struggled among the skyscrapers, as expected. But the new u-Blox unit had a noticeable more difficult time, than the GPS-500. I suspect it is due to the smaller antenna in the new unit.
I'm curious to hear observations and more feedback from other users. Ken and Terry just received their new u-Blox 5 USB GPS Sticks, too, so over the next few days we should be able to share more of our first impressions here in this thread. Stay tuned.