There has been a growing discussion about this in PHP internals but now there is a semi-official wiki page explaining what is going to happen with the replacement of APC by Zend open-sourcing their OptimizerPlus opcode cache.
https://wiki.php.net/rfc/optimizerplus
Right now it’s only a “proposal” but if you look at the internals discussion, it’s almost certainly going to happen, it’s just a matter of “when” not “if”.
Given that the few people working on APC would mostly likely stop and focus instead on Optimizer+, APC is now in theory, doomed. Which is a bit crazy considering how much code is out there to take advantage of it’s user cache (which is significantly faster than say memcached on a local single server). OptimizerPlus has no user-cache shared memory support at all, it’s only an opcode cache.
Not sure why the benchmark uses “ancient” WordPress 2.1.1 but in theory this would give even the newest WordPress 3.5 a five to ten percent performance boost.