Christopher Kunz wonders in this new post about the filter extension that's been getting so much press in the PHP community lately - specifically about it being active despite not being finished.
Basically, what he [Ben Ramsey] conveyed to me (and his blog entry supports this) was not to use ext/filter or Zend_Filter at all. Nearly every second slide regarding functions of the ZF component or the extension contained remarks like "This doesn't work yet, it's a TODO", "this won't validate XY properly".
Of course, other community members (Pierre-Alain Joye and Ilia Alshanetsky) come back in the comments to refute Christopher's claims. They note that it's not the filter extension that has the problems, rather that some of the features are missing outside of the core filtering functionality.