At the Mozilla "open house", Mike Schroepfer, Mozilla Corporation vice president of engineering said that beta 5 of Firefox 3 will come out next week. It will be the last beta before release candidate 1, which is due for May; Firefox 3 should ship in June or before, if possible.
Schroepfer said, Microsoft's stated support for open standards (like CSS 2.1) is "a huge win for the Web." But "I wouldn't call it 'vigorously embrace,'". Lots of old standards are still not used.
Firefox will support HTML 5, which has a spec for offline access. This will make Google Gears obsolete, he said.
Firefox 3 will have less of the "Firefox look" and appear like a native app on Windows, Mac and Linux. It will support skins so you can pick your favorite look. Nearly everything is in the same place, but the back button is about twice as big.