Definitly interesting. With how dirty my bike gets on a regular basis just riding in the rain, I'm not sure I would want a weapon that I might use to try and save my life just chilling out there on the side. I think I would be paranoid to leave the bike too, not knowing when some idiot might come up and try to steal or damage it.
It would be nice for having the ability to have more firepower while still on the bike.
If they were only fair weather riders with duty that doesn't take them away from their bike, it would be a great addition, but those guys are out in all weather, and are often on traffic duty where they park the bikes and walk away to direct traffic or whatever. I am interested to see what different department policies would be on this issue.