Latest rumour running round the Hill is that Jack Layton will "twin" the next confidence vote, whenever that may be held.
Angry in the Great White North has the best analysis of the reasoning behind Layton's offer (if true).
If Layton has decided to twin the vote, Ed Broadbent is the most likely candidate to abstain from voting.
Broadbent is not seeking re-election because of his wife's illness. He would have the most legitimate reason to absent himself from the vote, and in so doing, could not be criticized for playing mere partisan games.
It would also be an act of compassion and statesmanship towards an MP who himself is severely ill.
He has also publicly stated that he considers Tuesday's vote to have been a non-confidence vote. His abstention would underscore that statement: this vote is not really necessary, because it has already been taken.
Any of the NDP caucus could be absented, but only Ed Broadbent has the stature, as a former party leader and widely-respected parliamentarian, to make a simple parliamentary practice into a grander gesture.
UPDATE: Ed Broadbent has announced that he will sit out the next confidence vote, thus allowing Darryl Stinson to return to British Columbia for surgery.