"Possible" is a very vague word
It's "possible" that George W. Bush will submit and become a Muslim tomorrow.
It's "possible" that Alex Rodriguez will quit baseball and devote himself to charity.
It's "possible" that AA, BA & IB will merge.
And, in fact, the AA+BA+IB merger is the most likely scenario of the three I listed above.
So, now, you can quote me as having said "the "AA+BA+IB merger is the most likely scenario".
Personally, I'd bet on the snowball in hell first...antitrust immunity (a la SkyTeam, or UA/LH) yes, merger - no.