The way I see it, the future is on the enlargement of these so called political blocs. We've seen the growth of the African Union, European Union, BRICS, USAN (Union of South American Nations), and now ASEAN.
Membership shouldn't just be limited to or constrained to geographical location, but should be based on ideological pursuits. Most of the countries in ASEAN are democracies (republics: Indonesia, Philippines; constitutional monarchies: Thailand, Malaysia, Cambodia; absolute monarchy: Brunei; military government: Myanmar). Overall, the majority of ASEAN nations are democracies with a lively citizen participatory representative government. This aspect makes Turkey, a democracy, an ideal partner and an ideal member. Besides, Turkey is a large nation (80+ million) , with a relatively healthy growth rate and a healthy gdp per capita. Secondarily, Turkey is an advanced military power with a healthy indigenous military industry.
Imagine the possibilities in including Turkey into ASEAN.