Is the thunderbolt to ethernet adapter backwards compatible? Could I connect a thunderbolt-equipped device to an ethernet port.
It is a Gigabit adapter, which on the Mac needs a TB port. The Ethernet can be any speed. Not certain what you mean by 'backwards compatible'? If you are asking can it be plugged into a mini display port mac, the answer is no.
Yes I want to plug an ethernet cable into my computer and then into the adapter, using the thunderbolt end to connect thunderbolt devices. Possible?
It is a TB-to-Ethernet adapter, not an Ethernet-to-TB adapter. There are protocol issues, too. A TB-to-Ethernet adapter takes Ethernet frames in/out and passes them to your Mac's TB bridge (you can see it in System Preferences -> Network). The Ethernet port/driver cannot convert ethernet frames into TB packets.
Why not directly plug (and also daisy chain) TB devices directly with the TB port on your computer, if it already has one?
Well it doesn't have a TB port... thats my problem. Is there a thunderbolt to ethernet converter? Some card I could buy?
I am not aware of TB switches. They may be available next year.
You may also want to watch this space (These are TB-to-PCIe)
http://www.sonnettech.com/Support/charts/thunderbolt/index.html#ethernetadapters gigabit
Thunderbolt to Ethernet adapter
