I tested it here on my u430 (HD4400) and yes, it does seem to work. There are some strange delays sometimes (after sleep?) but it is still workable.
From my understanding of the patch (avoiding a forever loop around a failed IOLockTryLock), the real problem probably exists somewhere else and this fix is just masking the resulting hang (may be unstable, as the only reason an IOLockTryLock would fail consistently is if some code locked the lock somewhere, but failed to unlock it). I suspect there is a failure case somewhere or conditional specific to unsupported graphics devices that leaves the lock acquired instead of releasing (eg. case never tested with a real Mac).
