The interoffice mac zipper is a deal-killer for me. I don't need teeth marks on my MBA. It would also be nice to find even one real person who has seen/purchased one.
I purchased one: ordered on Thursday, shipped on Friday, should arrive tomorrow or Tuesday. I think the ManillaMac looks really cool. I opted for the InterOfficeMac ( http://www.interofficemac.com/ ) because it looks to me like it offers more actual protection for the MBA, and I didn't think that dealing with the little string closure was going to be a good solution in the longer term. I am assured by the owner, who does return emails promptly by the way, that the product fits like a glove, offers good protection, and that the zipper will not come in contact with the laptop.
All in all, while I do wish Jonah & Claire all the best, the InterOfficeMac just seemed more substantial & functional while ManillaMac looked more like a gimmick. We'll all know for sure soon enough.