Probably easiest if you call/email us directly.
omnifocus@omnigroup.com or 800 315-6664 or +1 206-523-4152
If you haven't synced your iPhone/iPad yet, they still have a copy of the latest. It may be as simple as letting one of them sync, which will warn you that they don't match and ask which one you want (sync or local, I think the options are).
Also, iDisk should still have a copy of the iPhone/iPad database, which you could manually copy down to your macbook air.
So, your data is almost definitely still available, but you may want one of our Support Ninjas to coach you through retrieving it, to help make sure you don't lose it in the process of trying to save it. They answer phones and email until 5 pm Pacific time.