Since you have pocket A's, you can play it but you need to be very confident in your game. The odds are very good that your hand will not improve, so you need to ask yourself if you are good enough to play just your overpair. If I didn't have good reads on my opponents, I would lay it down if:

1) Agressive betting before the flop - because you have no low, and people are acting like they do (and they could have that last A);

2) The flop misses your flush draw and people begin to bet.

As you can see, one or both of these is likely to happen, so laying down will probably be your play.

Now, that said, if you have position, potting could be a nice play pre-flop. Since you have three aces, no one may have one (At a full table, is extremely likely some one has an Ace. I figure the odds are (47!-16!)/(48!-17!) no one does. (Is this right? If wrong please let me know)). That said, with only one A out there, the odds someone else has A-2, or even A-3, is small, so who could call a pot sized bet? If you can narrow the field enough, then you may be in great shape. This is why you need to be confident in your game.

IMO,three of anything (but aces) is not playable in any type of Omaha. Three aces, well, you have an overpair but nothing else, so the ice is always thin. Always.