I found out yesterday that the American Ultimate Disc League (AUDL) started up last month: theaudl.com
Teams in Detroit, Indianapolis, Lexington, Columbus, Buffalo, Philadelphia, Connecticut, & Rhode Island. The season started in mid-April, playoffs in late July, & championship game in the Silverdome August 11th.
Word is the these teams can't yet compete with the club teams that typically make it to Nationals, but it's a start. I plan on checking out a game in Indy this summer, maybe stopping in Columbus 7/22 on the way home from Charlotte.