I am officially a QA Engineer but I still help out in Build from time to time. Most recently, I have been working on getting trunk releases automated with our release framework and Buildbot. Rob, Paul, and John both spent considerable time getting automation going for Fx2 and Tb2 releases. With that up and running it has saved a significant amount of human time on recent Firefox and Thunderbird point releases. I have been tasked with getting the same system up and running for trunk releases. Right now, that specifically means Fx3 betas. With tons of support from co-workers work on this is progressing nicely (thank you Nick, Rob, John, Paul, and Coop!).
For those interested, my work is being tracked in bug 379278.
For now, alphas and betas are being done by hand but by the time Firefox 3 Beta 2 is up for release I hope (and intend) to be able to have the automation do some or all of the process.