Well, "need" is subjective, but subpixel rendering introduces costs elsewhere in the system, so the threshold to turn it off might reasonably be lower than absolute parity with print.

In particular, subpixel rendering introduces performance and interoperability problems when the text is rendered on a layer that's semitransparent, rotated or used on more than one physical display (or that may become one of those things in the future -- that's the really tricky part). Everyone agrees it's absolutely needed on traditional low-dpi displays, but whether it remains a good idea or not on "retina" displays is a judgment call.