Whoa! Very exciting! I can't wait to hear who it is.
Seems pretty wide open as far as the possibilities. Here's how I'd rank what tomorrow's announcement might be from most to least likely:
Allegiant to Hawaii
Spirit to Las Vegas or Dallas/Ft. Worth
Silver Airways offering some intra-Idaho or Idaho-Montana service similar to Big Sky
American adding Boise to Dallas/Ft. Worth
Alaska Airlines (technically a new carrier) adding mainline 737s on Boise to Seattle
*All below I'd consider extremely unlikely*
Virgin America to San Francisco
JetBlue service to New York or Long Beach
WestJet adding Boise to Calgary or Vancouver
Hawaiian adding a nonstop to Honolulu
British Airways to London Heathrow (LOL!)
But that's just my guess! Very cool, and congratulations ATLonthebrain! You and your team are a service to our community.