Update: 1Password 2.9.19 beta 3 is out with support for Safari 4. You can use Check for Updates to grab it, but keep in mind: it's a beta. If you aren't used to downloading these, check out the simple instructions in the final paragraph below.
As you may already know, Apple released the final, shipping version of Safari 4 today during its inaugural WWDC '09 keynote. You can install it, but be warned: the 1Password plug-in does not work in the officially shipping version of Safari 4 (it works fine in the Safari 4 beta though), so you will (very temporarily) be without your 1Password data if you install Safari 4 right now.
For a workaround, you can, of course, opt to hold off on installing Safari 4 until we can ship at least a beta update. Since we know you probably won't wait, you can keep 1Password running in the Dock, always waiting for a quick manual copy and paste of your login info.
Naturally, we are already hard at work on updating 1Password for Safari 4. If you just gotta install the new Safari as soon as possible, open the Updates panel in 1Password's preferences and enable checking for betas. We hope to have beta support for Safari 4 by this evening (note: hope). Otherwise, if all goes well, an official update should be out (note: should) by tomorrow.
David Chartier
Chief Media Producer