OAS Secretary General Jose Miguel Insulza has recently told reporters that he is considering the revocation of a 1962 OAS resolution that condemned and excluded Cuba from membership in the OAS. Insulza believes that the resolution is now "obsolete."
The original document, linked here, was based on the perceived communist threat during the 60s. Cuba was excluded from membership because:
"The present connections of the Government of Cuba with the Sino-Soviet bloc of countries are evidently incompatible with the principles and standards that govern the regional system, and particularly with the collective security established by the Charter of the [OAS] and the Inter-American Treaty of Reciprocal Assistance."
(This resolution also came after Cuba was attacked by a failed US-planned invasion at the Bay of Pigs.)
Insulza also mentions that 31 of the 34 members to the OAS have diplomatic relations with Cuba. And, its safe to say that the "Sino-Soviet" threat is not what it used to be. Cuba's further integration with the rest of Latin America will possibly be discussed at the upcoming Summit of the Americas in April, where US Pres. Obama will attend.