In a recent article on Sitepoint about the release of Google Chrome, there is a mention of the two digits version number bug that Opera had to deal with in the past.
However, it’ll be interesting to see whether or not Google will have to address the double-digit user agent problem which Opera encountered when moving from version 9 to 10. Although browser sniffing is a terrible practice, many sites check the first digit of the browser version. Therefore, Opera 10 was identified as Opera 1 and the site was blocked or downgraded. The issue is unlikely to affect Google to the same extent, but we’ll know more when Chrome 10 is released in a few months.
Firefox has also decided to accelerate its release scheme by publishing a roadmap showing that they will get a double digit user agent around 2012. Microsoft is around the corner too. Probably many old unmaintained sites will break. We are living interesting times.