The article is slightly biased towards Chrome.
Chrome suppsedly wins the ACID3 category only by looking at the screen refresh, which may be down-prioritized (and rightly so) to execute JS, etc. The Acid3 test accounts for this, and gives the test timings by clicking the A in Acid3. On my 3-year old laptop, the timings are:
Opera 10.50:
Failed 0 tests.
Test 26 passed, but took 353ms (less than 30fps)
Test 65 passed, but took 138ms (less than 30fps)
Test 69 passed, but took 16 attempts (less than perfect).
Test 79 passed, but took 41ms (less than 30fps)
Total elapsed time: 1.45s
Chrome 4.0.249.89:
Failed 0 tests.
Test 14 passed, but took 44ms (less than 30fps)
Test 15 passed, but took 42ms (less than 30fps)
Test 26 passed, but took 116ms (less than 30fps)
Test 69 passed, but took 91 attempts less than perfect)
Test 70 passed, but took 44ms (less than 30fps)
Test 71 passed, but took 49ms (less than 30fps)
Test 74 passed, but took 45ms (less than 30fps)
Total elapsed time: 2.91s
Safari 4.0.4
Failed 0 tests.
Test 00 passed, but took 91ms (less than 30fps)
Test 26 passed, but took 98ms (less than 30fps)
Test 43 passed, but took 51ms (less than 30fps)
Test 65 passed, but took 41ms (less than 30fps)
Test 69 passed, but took 46 attempts (less than perfect).
Total elapsed time: 7.84s
On my computer Chrome uses twice as long for Acid3 as Opera, uses too long time on almost twice as many tests, and still Chrome wins. And no data to back it up. Unless this has been checked carefully on the test system and measured differently BY THE ACID TEST ITSELF, there is no way Chrome is the sole winner of Acid3.
If the dubious ACID3 test results are dropped, the results are:
Test wins:
Opera 7
Chrome 6
Safari 5
Firefox 4
Internet Explorer 2
Category wins:
Opera: 4 wins
Safari: 3 wins
Firefox: 3 wins
Chrome: 2 wins
To me, it does not look like Chrome is the winner. Opera is.