Actually, I would argue against either more Earth-based searches, or instruments in LEO, for a number of reasons:

1) Earth-based telescopes can only scan the night sky, away from the Sun, due to the dimness of the objects being sought. All three of the near-hits this year have been blindsiders - coming out of the Sun.

2) Earth-based stations are also too subject to the vagaries of weather.

3) The atmosphere filters out pretty much everything except for visible and radio waves.

4) All Earth-based and LEO systems have to filter out a lot of "noise" in the form of debris and satellites in cis-GEO space.

Personally, I'd put one at the EML-1 point, where over the course of a month the whole sky can be imaged in a full-spectrum of wavelengths. There's little or no man-made debris to filter out. Weather is a non-issue. It also doesn't require the delta-V capabilities of a lunar landing, and can provide an initial function to an eventual station there.

The Decadal Survey of the National Academy of Sciences calls for an All-Sky Synoptic Survey Telescope based in space. The NExT plan calls for a visit to the EML-1.

Sounds like a perfect match.

Ad lunam,
Kadet Ken