Aer Lingus to leave Oneworld?
 

Have a look at the "Other European FFPs" section:
http://www.flyertalk.com/forum/showthread.php?t=343881

While it is only a rumour for the time being, it seems perfectly believable to me given EI's strategy (including the massive change/near cancellation of the TAB program: after October 31st, only existing Gold Circle members can accrue and redeem miles).
Let's see what news the next few weeks bring, anyway I thought it might be useful to include a link in the OneWorld forum.

Cheers
Luís

Aer Lingus is a ridiculous excuse for an airline, honestly, so I'm not all that surprised. Possibly the worst in OW?

That rumour has been around for several weeks, along with other rumours about massive job cuts, aircraft purchases, etc (yes, the rumours are often contradictory). Doubt current EI management would commit to anything until the airline is sold, and the new owners can decide. Arguably exiting OW now would lessen the airlines value and the directors could be liable for the monetary loss (of course one of the rumours is that existing directors/management are putting together a bid, in which case reducing the price may be in their private interest -- and the Irish government may well play along). Lots of money to be made in DUB these days.