However, we have to take into account that Franz Ferdinand, while an inbred genetic cul-de-sac (like most of the Hapsburgs) was also a fairly lucid and potentially capable monarch. I think that we can safely say that Franz-Joseph is going to die round about the time that he did in OTL. If we can delay war until then, one could see considerable changes in the administration of the Austro-Hungarian Empire (FF was a key supporter of the "tripartite solution" aimed at creating a third kingdom for the Slavs).
As a result, WWI may happen, but under very different circumstances and potentially, may not even happen at all. For all the talk of the inevitability of the Alliance System leading to war. It wouldn't take much for cooler heads to prevail in a crisis; a more powerful Chancellor in Germany willing to support the Reichstag rather than the Kaiser, a more pacifistic Liberal Party, another revolution in Russia, all of these could quite easily occur before another war potentially broke out.