Want to be on the bleeding edge of Firefoxiness? Go alpha.
Just as we're all enjoying the newness of Firefox 3.6 along with our fancy (or gaudy) personas, Mozilla developers have dropped an early version of Firefox 3.7 that's ready for alpha status.
Of course, those keeping up with the nightly builds of Firefox will say that 3.7 has been available for some time now; but this one is alpha, making it a little bit more ready for developer consumption.
New in Firefox 3.7 is a newer Gecko 1.9.3 engine, support for WebGL, SMIL animations in SVG, and CSS transitions (partial).
We should mention that Mozilla last month dropped Firefox 3.7 from its release schedule in favour of concentrating on Firefox 4.0, so expect the efforts made in 3.7 to eventually evolve into the next major release.