Parry! Dodge! Spin! is an entertaining and informational rogue blog written by Valenna. He has brought up an interesting idea: in some instances, in some situations, rogues can be viable main tanks.
To understand this better, you first have to read his earlier post: Dirty Tricks To Surviving. This should be required reading for every rogue that out aggros the tank in a PuG. Obvious to some, but then you come across a rogue that doesn't understand why they are getting rezzed every five minutes.
After that, check out Dirty Tricks To Tanking. Valenna recommends the Surviving tricks minus the deaggro moves. Then he recommends piling up the Stamina gear, a Medallion of the Alliance to remove impairments and have some heavy dps and a back up tank along. With this set up, he has tanked Old Hillsbrad and Steamvault.
Any one else tried a non-standard role and survived? Any other Rogues pull off the tanking role with some cleverness and forethought?