The try for the Guinness World Record for the single most downloaded piece of software in a single day has begun. Mozilla is keeping careful watch as its servers will attempt to handle millions of requests for Firefox 3.0.Techachino itself has counted for at least one of those downloads, of course, as we’ll be updating our own copies throughout the day. We don’t expect any major surprises with the software itself, since RC3 to us looked very solid, with the exception of some screen refresh problems that, in our testing, we tracked down as being caused by other software, not Firefox.

We did get one surprise this morning, however: Mozilla’s developers’ blog, from which we get release notes and comments on active projects, is down this morning. We hope to see that up soon so we can let you know if any RC3 issues that we missed were found by others and fixed.