Denise Ho, a Microsoft product manager working on the MSN Search Toolbar, has this update on tabs:
Our goal in delivering this feature was to give IE users a tabbed browsing solution to enhance overall online search and browse experiences prior to the official release of IE7 without them having to install a completely new browser.
Many of you have reported a flicker when you switch tabs. We understand that this is bothersome and are actively working on improvements to reduce the tab flicker. There have also been reports of issues associated with tabs and using F11 in IE to get to full screen mode. We are also looking into a fix for this.
Give MSN credit for linking to at least five posts criticizing the performance and implementation of the tabbed browsing feature in the latest MSN Desktop Search toolbar (including mine, but not this one, to no one’s surprise). An improved version of the toolbar should be available soon, they promise.