If my traffic for firefox is 42% today up from 23% on the second of this month and IE traffic is down from 61% to 45% on the same dates. This post and this post take on new relevance!
It's the power law at work; the adoption of Firefox is accelerating (I noted on December 14 it was at 10 million downloads).
TechWeb - The number of downloads of Firefox has topped 25 million, indicating that the open-source browser continues to make gains in the market dominated by Microsoft Corp.'s Internet Explorer. [Yahoo! News: Reader Ratings]