We've been hearing that rumo(u)r for several years now but as of my last visit (June), all was still on UHF. A variation of the rumor I've heard is that they (and SIM) will go to the RSP! Can't imagine they'd abandon such a new Motorola system, but you never know.
They will change for sure, somewhere between 2007-2008 on the Motorola digital 3600 bauds, the city of Montreal system. They have not yet choose what it will be: all encrypted or just some talkgroups.