Allow Rank reordering on the Task Board

Allow Rank reordering on the TaskBoard. I would like to be able to adjust the relative rank of my tasks. The rank should be contained within the column. If I have 3 tasks in the "ToDo" column. I would like to order them as A,B,C then be able to change it to C,A,B when task "C"
needs to be done (moved to InProgress) prior to task "A".

http://forums.atlassian.com/thread.jspa?messageID=257364082
has a good discussion about this (but I could not find an enhancement or existing issue requesting the enhancement).