A quick update:
On Tuesday 5-13-14 I logged in P25 traffic on 155.190 MHz. It was full scale on my BCD396XT in Latham. NAC showing was 293. The transmissions were very quick so I can't confirm if encryption was being used. Today (5-14-14) had regular analog traffic on 155.190 with the CTCSS tone of 110.9 Hz. This seems to line up with previous loggings of P25 traffic on 155.700 MHz., also with a NAC of 293. Those transmissions were encrypted.
If I had to guess, as the completion of the UCC gets closer, they will be doing more testing of the P25 equipment. And, if I had a dollar to bet, once the UCC goes online, so will SPD's P25 equipment (and my guess, probably full time encryption).
Kevin