Next January the Asean community comes into being, at the moment I have a retirement visa and if I wish to travel outside if Thailand I an required to purchase a re entry permit. So, from next January (2014) if I go to any of the countries within the Asean group will I still need to purchase a re entry permit?

Yes, you will still need a re-entry permit. (And a visa as normal to enter other ASEAN members state. It changes nothing for you regarding immigration rule).

In any event, this would presumably only be possible were ASEAN members to conclude a Schengen-type agreement - which Thailand, of course, would presumably be free to opt out of just as the UK has done from the EU agreement.