Gecko 1.9.0 (and Firefox 3) are so very very close to being done (finally)... after having worked on it for almost three years now, I'm pretty happy.  We ended up in a good place with Cairo: we're shipping Cairo 1.6.4 plus a few upstream patches to our 165+ million users.  The patches should be included in 1.6.6 -- we still have some patches that aren't upstream, such as changes to the Win32 font rendering scale and a hard-cap max font size, but they're minor.  (If anyone's interested, our patches are always listed here.)  Cairo has let us create a good foundation for future graphics work, including hardware acceleration and advanced effects.  We should be able to build some interesting things on top of it in the future!