I found this story yesterday:
Rep. Ron Kind says that he'll cast his super-delegate vote for whichever presidential candidate wins the most votes in his congressional district in next week's Democratic primary.
Kind would also like to get rid of the super delegate system altogether, writing to Howard Dean that "No person, regardless of position or office, should have his or her vote count more than anyone else's"
Fellow Wisconsin Representative Steve Kagen has made the same pledge.
Senator Feingold has hinted he'll do the same.
Moreover, there has been a switch by David Scott(GA-13) to Obama after Obama won 80% of the vote in his district on February 5th.
Note: A name in italics mean they endorsed Clinton, but their constituents chose Obama. Underlined means they endorsed Obama, but their constituents chose Clinton
Further note: Some of these may be incorrect, as tallies by Congressional district are not yet available everywhere. This may also not be comprehensive.
Arizona
Gov. Janet Napolitano
Rep. Raul Grijalva
California
Rep. Maxine Waters
Rep. Doris Matsui
Rep. Mike Thompson
Rep. Lynn Woolsey
Rep. Laura Richardson
Rep. Diane Watson
Rep. Xavier Becerra
Rep. George Miller
Rep. Linda Sanchez
Rep. Zoe Lofgren
Rep. Adam Schiff
Colorado
Rep. Diana DeGette
Delaware
Gov. Ruth Minner
Iowa
Rep. Leonard Boswell
Maine
Gov. John Baldacci
Maryland
Gov. Martin O'Malley
Senator Barbara Mikulski
Rep. Dutch Ruppersberger
Massachusetts
Senator Ted Kennedy
Senator John Kerry
Governor Deval Patrick
Rep. Bill Delahunt
Missouri
Rep. Emanuel Cleaver ? (looks like it based on Kansas City's heavy Obama vote, but Clinton did narrowly win Jackson County)
New Hampshire
Rep. Carol Shea-Porter
New Jersey
Rep. Donald Payne (almost certainly)
Rep. Steven Rothman
New York
Rep. Yvette Clarke
Rep. Gregory Meeks
Rep. Ed Towns
Virginia
Rep. Rick Boucher
Washington
Senator Maria Cantwell
Senator Patty Murray
Rep. Jay Inslee
Rep. Norm Dicks
Of course, this doesn't include those who haven't yet endorsed.
Anyway, the point is that this is the right thing to do, and I'd love to see every super delegate pledge to abide by this rule.
Update: Civil rights icon, 1960's student John Lewis will cast his vote for Obama, who handily won GA-5
Also, Senator Boxer had pledged to vote for the winner of the California primary. Although I'm not supporting Hillary Clinton, this is still definitely the right thing to do.