On Pierre's blog today, there's a release announcement about the "long awaited for" version of his Filter extension - version 0.1.0.0.
This release will be included in the upcoming PHP 5.2.0RC3, which is likely to be the last RC. Please report any trouble you find, and post your feedback (here, on the pecl-dev mailing list or in the issue tracker), it will help provide the best possible extension in the 5.2.0 release. A stable filter release should still hit the road this year.
Feature additons for this release include an input_get_args method, support for PHP's pcre expressions, JIT support, and support for custom decimal spacers. Several behaviors were changed as well, including when a value is FALSE or NULL, updates to the integer/float parser, and the default filter now being set to "raw".