All new sites, starting with Troop B and moving eastward as trunk sites are replaced with new equipment, will end up being P25. That process will take some time, maybe years, as there is only so much money allocated for new equipment each year.
Since 9600 baud systems are true P25, there will be no analog audio on them.
I wonder how they will handle simulcasts on older sites? Will traffic that originates on a new Troop B site be transmitted on an older TG in analog on a Troop C site? Or will they add new digital talk groups on the older sites since those presumably can handle digital audio already?
I guess we'll have to wait and see. I wonder if the XT scanners can be programmed as multi-site systems with some sites set up as 9600 baud and some as 3600 baud? Since each site is in reality it's own trunk system, I can't see why not, but I'll have to wait until I get home and can play with ARC-XT.
I have the same question about the PSR600/Pro-197, but since I don't use mine mobile, it's more curiousity than anything else.