Or you simply go to the online Apple store: http://www.apple.com/shop/accessories/all-accessories/storage#!&f=thunderbolt2&fh=40aa+401f
I've narrowed the list to TB2 storage items only. There are TB1 and non-storage items as well.
@theSeb has given the official Thunderbolt website that lists most Thunderbolt hardware. When compared to firewire and USB there is a much bigger diversity. Don't forget that you can simply buy a TB-PCIe enclosure and use standard PCIe cards (in the beginning the only way to get 10GbE networking, nowadays there are quite a few 10GbE-TB cards/devices available...and yes, you do want them in a separate box, they get hot during operation).
I've narrowed the list to TB2 storage items only. There are TB1 and non-storage items as well.
@theSeb has given the official Thunderbolt website that lists most Thunderbolt hardware. When compared to firewire and USB there is a much bigger diversity. Don't forget that you can simply buy a TB-PCIe enclosure and use standard PCIe cards (in the beginning the only way to get 10GbE networking, nowadays there are quite a few 10GbE-TB cards/devices available...and yes, you do want them in a separate box, they get hot during operation).