It doesn't matter whether Chrome or Firefox is more widely used, as long as IE8 continues to be the newest Internet Explorer available for Windows XP.
Attention, web developers: how many lines of code did you change when you learned that Chrome was about to surpass Firefox in usage terms? I'll even arrogantly assume that if Chrome suddenly claimed 51 per cent of the browser market, then you wouldn't change a thing. In fact, if Chrome did have that percentage of users, you'd be even more frustrated that your ability to take advantage of its capabilities was restricted by the install base of IE8.
To see what web developers are up against, here's a graph from StatCounter that shows IE8 usage way out ahead of the competition, with 24 per cent of the market.
Now take a look at the Trident column of the HTML5-compatibility matrices — the magic number that represents IE8 is Trident 4.0 — anything green and with 5.0 in it just isn't going to cut it.
In case you think it looks reasonable, take a peek at the compatibility for the Canvas tag and the various HTML5 media tags; Canvas and media tags are where a lot of potential lies within HTML5, and developers are restricted from using it easily and natively in production thanks to the quarter of the online population using IE8.
The answer for how we got here is easy; Windows XP's usage currently sits at a little under 50 per cent, and, despite the efforts of Microsoft, it refuses to quickly go away. There are ways to hack around IE8's limitations, and a lot of them involve Flash, but it's nice to know that an ageing operating system will still be providing an attack vector for nefarious operations, and keeping the ignorant and careless doubly exposed.
HTML5 promises to do away with much of the pain of web development, and if one could restrict development to Chrome, Safari, Firefox and IE9 and IE10, it could be a glorious wonderland of possibilities. Instead, developers need to constantly consider the experience in a browser that passes the Acid2 test, but fails at Acid3. At least IE8 gives full CSS 2.1 support; deprecating and ignoring IE8 isn't an option, and will not be a viable one for a while.
Prototypes, tech demos and sites with limited use cases will be able to embed Canvas, SVG, and video tags with little ill effects, but the big players on the web will still have to cater for the most popular browser version on the internet.
Up against IE8, the bickering of whether Chrome or Firefox has the biggest number of users is simply arguing over scraps at the dinner table. Instead of looking at moving users to a particular brand of browser over another, there needs to be a push to move users onto a modern browser platform, from any vendor. Internet Explorer 9 is as acceptable as Chrome in this case.
When modern browsers become the overwhelming majority, I will welcome it heartily, but that day is at least a couple of years of compatibility libraries and workarounds away.
It could be worse; we could still be dealing with IE6.