According to Microsoft Watch, IE 7.0, which will be out in beta this summer, will be a tabbed browser.
Sources say that IE 7.0 â€“ which is code-named “Rincon,” they hear â€“ will be a tabbed browser.
In addition, some other features in which developers might be interested are:
IE 7.0 will feature international domain name (IDN) support; transparent Portable Network Graphics (PNG) support, which will allow for the display of overlayed images in the browser; and new functionality that will simplify printing from inside IE 7.0, partner sources said. The new browser also will likely include a built-in news aggregator.
As far as CS 2.1 goes:
Partner sources say Microsoft is wavering on the extent to which it plans to support CSS2 with IE 7.0. Developers have been clamoring for Microsoft to update its CSS support to support the latest W3C standards for years. But Microsoft is leaning toward adding some additional CSS2 support to IE 7.0, but not embracing the standard in its entirety, partners say.
I sure hope this is true.