Apple Support, in a pretty terse document:
The eligibility period for the MacBook Air (Original, Late 2008, and Mid 2009) Hinge Quality Program has ended.
The eligibility period covering this issue has ended.
I had forgotten about this situation, but I linked to a support article about it back in 2009.
The URL I linked to back then now redirects to the short announcement quoted above, but here is what it said:
Learn what you can do if you experience one or more of these issues with the hinges on your MacBook Air.
- Unable to close lid completely.
- Broken or cracked plastic near one or both of the hinges.
- More than one inch (2.54cm) of free play while opening or closing the lid.
- Lid falls freely into closed position from a 30-degree open position. (From a closed position, open the lid approximately 30 degrees and let go.)
You can take your MacBook Air to an Apple-Authorized Service Provider or Apple Retail Store for evaluation and repair if necessary, even if your product is out of warranty.
If you previously paid for a repair for hinge-related issues that were not caused by accidental damage, you may be eligible for a refund. Contact Apple for more information.
That last bit is important, as Apple had previously been treating failed MacBook Air hinges as if they were cases of accidental damage.