As reported in this week's magazine, actor Dean Winters spilled the beans to us that Mayor Bloomberg will make a cameo in an upcoming 30 Rock episode called "Subway Hero." We suppose that's exciting, but what's got us really chuffed, stoked, and psyched is the return of Winters himself as Liz Lemon's sleazy, pity-sex-giving ex, who appears opposite Bloomberg in a one-on-one scene set in City Hall and, he explained, elsewhere. "It's probably one of the funniest things I've ever been a part of," he told us. 30 Rock devotees will recall that Winters's character, né Dennis Duffy, called himself "the Beeper King" for his not-so-thriving pager-selling business. No longer. "The Beeper King has inherited a new moniker," Winters teased, "which I'm not allowed to share," Winters teased. Ohhhh! We started imagining the possibilities…