Gates announced Internet Explorer 7.0, designed to add new levels of security to Windows XP SP2 while maintaining the level of extensibility and compatibility that customers have come to expect. Internet Explorer 7.0 will also provide even stronger defenses against phishing, malicious software and spyware. The beta release is scheduled to be available this summer.- from http://www.microsoft.com/presspass/press/2005/feb05/02-15RSA05KeynotePR.asp
Hm, I don't see anything about tabs.
In the meantime, might as well download Firefox: