A new TenFourFox beta is out for testing. This is an important update as it's the first build under a new compiler and there were previous warnings that it would push minimum memory requirements up to 1 GB. I can echo Cameron Kaiser's finding that those fears have not come to pass. In my testing, memory use is up slightly, maybe 30-40 MB on average, not enough for me to care about. He also says he's eager for Leopard and G3 users to test this as he doesn't have a G3 or a Leopard machine, so give it a download.
In my couple of days testing, it's been stable. In that respect, TenFourFox remains as boring as ever. Page rendering seems less jumpy and a tad quicker, but that could be a placebo effect. Altivec acceleration has been added for pages that shadow out the background. This will make me hate web developers a little less. Also, clicking scrollbars and tabs with the window in the background are now active, like with Safari/TenFourKit.
Check out Cameron's blog for the longer version. His posts are always packed with information without being overwhelming to the layperson. Glad to see TenFourFox still has a bright future.
UPDATE: And for Leopard users, SeaMonkey 2.16b1 has been released.