Who will it be? Well folks, today’s the day. It’s the day you’ve all been waiting for, arguably one of the most anticipated days in franchise history: the Bruins will be unveiling their jersey sponsor this morning. In fact, by the time you read this, it’ll probably already be revealed, but as I sit here Wednesday night, it’s shrouded in mystery. The photo above is from an older Dunkin’ sponsorship, but they wouldn’t be a bad guess — second-biggest company in the state, ubiquitous presence in all aspects of Bostonian life. Hell, there are people in the state who would…