I'd be happy enough if it just supported memcached and APC, as the latter is the most supported (and fastest in my insignificant tests) opcode cache on both Linux and Windows, and larger sites obviously need memcached.
fyi, at least last I read internals, PHP 6 is no more (because of unicode/problems with approach). Next is PHP 5.4, which will incorporate many of the changes that were going into PHP 6.