Reports coming in of DST-related Snow Leopard issues

The workaround is apparently simple (if it hasn't already resolved itself after the cutover); just turn off the menu bar clock in System Preferences for a moment, and the problem should go away. On the other hand, the philosophical question of whether a system version that was billed as having no major new user-facing features outside of improved performance and stability should have arrived with so many fascinating quirks... well, good thing we got an extra hour of sleep last night.

Thanks to Gordian and everyone who sent this in.