Adaptive Supersampling

Subdivides the pixel until adjacent subpixels' colors all lie within a given threshold (or max number of subdivisions already done)

Jittering

move sampling location by random amount (adds noise to image)

These are combined in version 4.0.6 (available in the CS misc collection)

Light sources

point, directional, spotlight, spherical options. Shadow attenuations (through transparent objects) can be turned on or off.

Gamma correction

Not really a lighting issue, but it's available.