So I plugged my MBA using a DVI to Displayport connector (Apple) to my 30" Dell 3007WFP display (native resolution 2560x1600). The MBA only lets me go up to 1280 x 800. I think I know the answer (powered DVI connector) but before I go spend that kind of money on a monitor adapter, I am hoping someone has better news for me.... 
BTW, this monitor at 1280 x 800 looks insanely huge. No squinting at all!
BTW, this monitor at 1280 x 800 looks insanely huge. No squinting at all!