I consider most of Microsoft's products to be in a perpetual beta state. They often get rushed out the door with the attitude that any problems that crop up can be fixed by issuing patches later.
The only good thing I can think of about IE7, is that Microsoft is FINALLY fixing the horribly broken rendering engine in IE6 and bringing it most of the way up to full standards compliance. It will make the lives of web developers the world over so much easier, now that they'll have a more or less proper CSS2 implementation.
Otherwise, all the new features that are supposed to be so great about IE7 have been in Firefox for ages. Opera was doing something like tabbed browsing back in the IE4 days, and Mozilla perfected it. Firefox had the idea to shade the address bar yellow when on an encrypted connection, and idea that has been expanded upon in IE7. Firefox has long had the most complete and standards compliant rendering engine. It can't take the performance crown from Opera, but it's not too shabby.
Finally, since I doubt IE7 will do much to curb the massive spyware/malware problem plaguing IE6, I'll sit on the sidelines and use Firefox. Some day soon, I'll move further onto the sidelines and get myself a nice Mac.