Adobe posted new Pixel Bender releases for the Adobe MAX conference. The Pixel Bender Toolkit is newer than the one that shipped with CS4. Among other updates is the Pixel Bender Plug-in for Photoshop Cs4, which comes with a Gallery of 12 filters.
According to Kevin Goldsmith, the Pixel Bender Plug-in for Photoshop Cs4 "supports both Pixel Bender kernels [.pbk, "shaders" in Flash] and Graphs [.pgb, networks of kernels] and is accelerated for both GPUs and multi-core CPUs. You can now use the same Pixel Bender filter in Photoshop, After Effects and Flash!" Except the more complicated "Graphs" have to be assembled separately for the Flash Player, which also doesn't use the GPU.
Pixel Bender seems like a developer-only affair so far, although experiments by Pixelero and Mr.doob mentioned earlier in Spilling the beans on Pixel Bender, and ones by Frank Reitberger (promises the ‘Droste effect’) and Subblue (Guilloché Pattern Generator and Harmonograph) are enticing. In the near future Flash-based RIAs should benefit, and maybe there'll be some nice free float filters oriented to AE users. It's too bad Conduit for Flash Pixel Bender will be limited to Flash in it's initial release, although you can still roll your own with Conduit Suite.
Update: John Nack adds details in Pixel Bender arrives in Photoshop.