No it will not. From what I understand the HP-1 does not have a useable discriminator output, or a point inside that can be tapped. If you are wishing to use DSDPlus your best bet would be to get ahold of a cheap analog scanner that you could have a tap installed in.
Sorry, I don't. I wouldn't be surprised to see more commercial users move to MotoTRBO or NXDN.... Maybe even some of the hospitals, but this day and age who knows if they have any budget for that.
As far as everyone else goes, no changes that I'm aware of I've heard rumblings that some changes are coming for Elgin County however... Sounds like county fire and roads/works departments are all going MotoTRBO.