Well, I don't know if this qualifies as the kind of sighting you're talking about but I want to add this.
I visit lots of carrier stores to play with Windows phones because I don't own one yet. I seem to need a WP7 fix and I hope that doesn't sound too weird but, I stopped in a Sprint store here in Las Vegas and asked one of the reps to direct me to the HTC Arrive. He did.
He followed be there and began to talk about how great this phone is. To tell you the truth, I had to pinch myself as his enthusiasm. Then, he reached into his belt clip and handed me his HTC Arrive. "Here, hold it. Check it out".
I did.
This one had apps, facebook, email the whole nine. Needless to say, that Sprint store gained mad respect from me. But as I think of it, when I was in line to get badged for CES 2011, there was guy in another line with a Windows phone. I remember thinking, "I wonder if he would let me check it out?"