There's also other Winestripe themes available:
Right now, it only works in Firefox 2, but at least you'd be up-to-date on security fixes until support for Firefox 2 drops mid-December.
"Winstripe Classic" only works in Firefox 2. There's a "Winstripe Modern" theme on this site that, like Stratastripe, integrates some of the Winestripe theme with the "Strata" theme of Firefox 3.
You can download more than one theme and switch between them to see which one fits your needs best.