Ilia Alshanetsky has a very quick note today about the inclusion of libSQlite version 3.3.7 in the upcoming PHP 5.2 release.
I've just completed the upgraded of the bundled libsqlite in pdo driver from a fairly antiquated 3.2.8 to the latest 3.3.7.
Yet, another reason to upgrade to 5.2.0 when it comes out.
For more information on using PDO and the status of it, check out the PHP manual page for it, specifically this page for more on the SQLite drivers.