In this brief entry on the ThinkPHP blog (by bjoern), it seems that there's more than just talk about the Zend/Oracle deal.
While reading the tecosystems blog, I stumbled over Steven's entry "The Oracle M&A Q&A: JBoss, Sleepycat and Zend". It seems that at least Oracle's interest in Zend is true: "[...] and in one panel yesterday Zend's Doron Gerstel did little to deny the Oracle interest". Also, it seems that JBoss has been acquired for $485 Mio. by Oracle.
the Q&A mentions that Zend would fit in with their plans as an "in" to the PHP community and a way of increasing their growth in the database markets.