In an unusually anticlimactic product update, Apple (AAPL) quietly refreshed its $999 MacBook early Tuesday with a faster processor, better video chip and longer-lasting battery.

There was no hoopla. No press release. No “We’ll Be Right Back” sign at Apple.com — at least none that anybody with a Twitter account seems to have spotted. Just some new specs that matched down to the last gigahertz those released Saturday in a YouTube video by the Vietnamese website Tinhte.com.

It was the second major Apple scoop in a week in what has become a hotbed of supply chain leaks. A few days earlier, the same website had posted a video of a 4th generation iPhone that looked a lot like the prototype Gizmodo purchased.

Apple, like other U.S. manufacturers seeking to lower labor costs, may have shifted some of its contract work from China to Vietnam, where security doesn’t seem to be as tight.

Below: What’s changed in the specs.

• Processor: 2.4GHz Intel Core 2 Duo (same as 13-inch MacBook Pro) up from 2.26GHz
• Graphics card: NVIDIA GeForce 320M (same as 13-inch MacBook Pro), replacing the NVIDIA GeForce 9400M
• Battery: 10 hours (up from 7 hours), not user-replaceable
• Unchanged: RAM (2GB), Hard drive (250GB) and optical drive (8X SuperDrive) unchanged
• Price: $999, unchanged

See also:

• Apple (finally) updates its MacBook Pro line

[Follow Philip Elmer-DeWitt on Twitter @philiped]