In late 2008 there were news reports of the Transportation Security Administration requesting funding for newer, smaller radios that were supposed to help keep the security checkpoints quieter.
Now I have seen a report that the TSA at Newark Liberty Airport is using new Icom F50 portable radios at the screening areas. Interestingly, the person reporting this says they were using them on 172. 1500 MHz in analog mode (136.5 pl), but with voice inversion scrambling!
The TSA is apparently still using the APCO P-25 radios for other operations in Newark, and I have not heard this analog activity at other airports, but I will be looking for these changes as I travel this week.