Bigfug has now released a version of their inexpensive commercial product Frame Runner (Windows-only) that enables FreeFrame filters in CS3. It seems like the filters come separately.
FreeFrame is an alternative framework for developing video effects plug-ins and hosts on Windows, Linux and Mac OSX and was initially intended for use in VJ applications. Pete Warden provided a free FreeFrame filters and an AE plug-in to access FreeFrame filters on Windows and Mac OS X, but he didn't update his work for CS3. Pete appears to have moved on to Apple Motion (working at Apple), but the BSD licence will let you maintain the AE versions. His Freeframe filters are still free.