I guess Blizzard will have to end up flagging items for specs rather than just roles for this system to be successful. There is too many problems for feral druids, spirit cloth wearers and death knight weapons. If it was role based I could go in as enhancement shaman and get to roll need+100 for all gears that my spec and off-spec could use.. considering a dps shaman can be either elemental or enhancement.
If this system does not work with specs it will just be unfair to some classes. I wouldn't think I want to bring my restoration shaman if my off-spec is enhancement, I could just go as enhancement and get all the loots than just half of what I could use. Same with druids, I just go as dps and I then should be able to gear up a boomkin, resto and feral spec with need+100 with just the single role I signed up for.
Heck this system would make it even easier for me to get gears as a shaman (for example) than how it is today in most pugs.
---------- Post added 2011-10-07 at 07:55 PM ----------
I suspect you change role if the raid signs up again to get more people for a raid or something like that. Probably will work much the same as it does with 5-mans today.Does than mean you can change your role during the raid?