It can still end well - if one of the two aircrew did survive and is handed over unharmed it will probably go away quite quickly - but if Erdogan keeps upping the ante he will find himself very alone very quickly, NATO (or at least most of the member nations) are not going to go to the wall for him over this.
One would imagine the Yanks will tell him he either eats humble pie, STFU and never even thinks of doing this again or see the US-led support for the rebels switch to the Kurds, Assad's time in an "interim leadership role" grow a lot longer than it is now and the co-operation between Syria, Russia, Iran, the US and the rest of NATO over this (and other issues) get a lot closer.
One things for certain, Turkey is deffo supporting rebel groups (Turkmen/FSA) in Northern Syria - Vlad will now go after these groups now with no mercy. His ground attack aircraft will be supported by AA fighters and backed up by anti-air cover provided by the Moskva. The Turkish AF will effectively be grounded and helpless.
If it flies - it dies!