A while back, Hubble detected the smallest Kuiper Belt Object (so far) by detecting the diffraction effects of it occulting a reference star.

Are there any plans or studies for a telescope designed to detect objects using this occultation sensor technique? It could be used to detect dark objects in the outer solar system and beyond.

Thanks!

The Taiwan American Occultation Survey ( TAOS ) was designed to do this using ground based telescopes. So far (3.5 years) they haven't detected any.

There's a couple missions in progress, Kepler and CoRoT. While they're aimed more at exoplanet science and asteroseismology, the detection method is the same.

HST's detection of the KBO you speak of was a pure stroke of luck. It is not expected to be a fairly common occurrence.