There are different vision but I think we can almost agree to consider almost something as based on real fact.
First: Turkey has very capable and modern armed forces, all three branches, it is a long time Nato member and it can count from its full support.
Second: It's a muslim country, with a crushing Sunni majority, stable istitutions a staunch economy, a stable and popular moderate islamic government i.e. the living embodiement of the ultimate goal of all "arabian spring" movements
Third: Support to Syrian regime comes only by some of its minority group and with exception of Alawites itself is not even unanimous, so once the major units involved in repression would be destroyed or even simply unable they would not be replaced by newly formed units.
Fourth and more important: Turkey and the Arab league countries wouldn be surely more accepted by Syrians than Western (and above all American) forces and they would not even been shacked by all the defatigating democracy-building process that the latter have to put on as a moral justification of their actions toward its own public opinions.
Turkey can so simply start thing up, overthrow Assad, install a provisional government and get back as soon as possible and still would reap great political results in Syria and all M.O. and with all bill payed by gulf monarchies.