The MacWorld Expo is going on all week at Moscone Center, and there's been all kinds of speculation going on about the internets concerning what Steve Jobs was going to unveil at his opening keynote address this morning. Rumors ranged from the "definite" unveiling of a new Mac mini-based home media PC (and we chomped on that rumor like a bass), to the "unlikely" announcement of a new Apple-branded HDTV. What actually happened was......