There were several other rpg companies affected by this. (Strangely not Wizards). I'm sure it's just a glich they need to work out.

i pre-ordered the gathering storm also, and they haven't sent me any notice that the order will be unfillable either.

It could simply be that when Amazon doesn't have item X in stock they pull it so there's not a backlog of 3 months of orders with people whining about their inability to keep their stock info accurate. That'd be a nice change.

The Gathering Storm is back on pre-order at Amazon.com, but the GM's kit is nowhere to be seen

To me, living in Brazil, there's a huge difference ordering from Amazon or from other game stores. Books are not taxed by customs, and Brazilian customs usually allow everything from Amazon as a book. If I order from a game store, it will be taxed as a game and I'll pay 60% over total price (including shipping). Please, please, Amazon, can you sell me the GM's Toolkit and Gathering Storm?

Amazon.co.uk seem to be still selling FF Games and taking pre orders for the GM Tool kit and The Gathering Storm. I picked up the Core box set for £36 from Amazon UK, which is a bit of a bargain as it was over £60 a few weeks ago.