Maybe once Insteon becomes mature.  Right now I cannot imagine a pro installer brave enough to sell & configure Insteon.  Right now HAI is not losing anything by not supporting Insteon, other than in the DIY market.  Elk has an early lead with Insteon support, but I bet that was added more due to DIY requests than pro requests.  And I give Elk credit for trying, but due to issues outside of their control, the Elk support is not elegant or friendly yet.