Slew2 doesn’t act anything like Slew. What it does, is it puts a particular behavior on the extreme highs. Set to an intermediate value, it’s an acceleration limiter. Cranked all the way up… well, check out the video.
It behaves like one of the nodes in Average (also coming to VST) with a 100% cancellation, but the point of total cancellation is also the Nyquist frequency.
Slew2 produces a very natural-sounding brickwall filter exactly at that frequency, with the response falling off faster and faster until it’s totally gone when you hit the Nyquist limit (digital sampling theory: at 44.1K (CD quality) it is 22.05K where the treble cuts off).
Slew2 is available for free and instant download in VST/AU versions for Windows and Mac.