Or perhaps I should say "issues," rather than bugs. The Pretty Scary Update has been an exciting one, but it has a few niggles. If you've had problems with signs, fought with lag or struggled with slimes (let's face it, who hasn't?), then you may want to give this a try.
A full list of the issues addressed can be found here. If all goes to plan, Mojang will officially release 1.4.3 next Wednesday.