Does the MB Air with thunderbolt only connect with Apples Thunderbolt monitor? What are the options for third party monitors with DVI or VGA?
The MB Air has a Thunderbolt port but you can also just plug in a Mini DisplayPort with an adapter to a pretty much any monitor or TV you want. You can use a number of adapters such as Mini DisplayPort -> DVI or HDMI.
Mini DisplayPort to DVI on Monoprice
Mini DisplayPort to DVI on Apple Store
They're the same as for other computers with Thunderbolt:
You can use any Mini DisplayPort adapter that you might already have, or any that are available for purchase. I have my brand-new 2011 MBA hooked up with a Monoprice MDP->DVI adapter right now.