The Firefox 3 Download Day is still going on and so is the world record attempt. Update: Firefox 3 World Record is set.

The Firefox 3 download counter currently states 4.6m downloads and keeps going strong. Update: 7:20am EST The download counter is now over 6m. The U.S. accounted for almost half of these downloads.

I am downloading FF 3 right now and it takes a while to receive the 7.14MB file, but it is progressing.
The world record attempt for the most downloads in 24h is going on until 11:16 a.m. PDT (18:16 UTC) on June 18th, 2008. That's 11:16 a.m. in Mountain View, 2:16 p.m. in Toronto, 3:16 p.m. in Rio de Janeiro, 8:16 p.m. in Paris, Madrid, Berlin, Rome and Warsaw, 10:16 p.m. in Moscow, and June 19, 2008 at 2:16 a.m. in Beijing and 3:16 a.m. in Tokyo.
Download Firefox 3 here, if you have not done so yet.