I'm game. Most of it will be a walk in the park. We need at least 8 guildies to get guild credit I believe on 10 man raids and the old world stuff we will need at least 10 guildies since a guild gets credit if 1/4 of the 40 man is comprised of them. No one has to be super geared at 85 to knock this stuff out either. Plus it will help each member's personal achievements if they still have yet to get them.
Now that I think of it, most of the BC content will require us to have 20 I think for credit on the 25 man raids there. Here's something I remember reading from wowpedia.org:
Guild achievements are a combination of general, pvp and raid achievements earned through efforts of the guild as a whole. You will typically need 80% of a dungeon (4/5) or raid (8/10, 20/25) to be from the same guild in order to gain credit for events, with the exception of 100% for arena teams (2/2, 3/3, 5/5) and 25% for 40-man raids (10/40).
This might hold true still. I'll update the MOTD and get people interested in the event come Sunday. Since these are raids, we could pretty much invite most of the guild in to knock them out since I doubt we will hit the limit for guild members in the old world raids.