Daisy chain two monitors on a single thunderbolt port
You can chain up to 12 thunderbolt devices of any kind. If you want to connect a non-thunderbolt device, make sure you put it at the end of the chain.
Also keep in mind that Apple, for some reason, doesn't allow 3rd party-non-thunderbolt-displays chained directly after their own Thunderbolt Display. However it will work if another thunderbolt-device is inbetween.