Macbook Air battery time, take two

Anand has given a quick take on the battery life of the Macbook Air, which the Ars Technica review claimed was barely more than two and a half hours.
It seems that four hours and almost twenty minutes are possible.
This new value is indeed a good one for the type of usage, "Wireless Internet browsing and MP3 Playback", and the DVD playback measurement is also a good result.

The question now poses itself, regarding the first measurement: bad laptop or bad review? Ars review's are typically reliable ones, but some sloppy testing may have taken place, in order to be the first site publishing the review on Air.
Notebook Review also got the same values as Anand, so if you need that good battery life to buy one, well, you can now.