It looks like a new version of Internet Explorer 7 Beta 3 was put online for people to download. I’m sure that there hasn’t really been any changes but it does probably include some security fixes.
Now I don’t use Internet Explorer that much but I definitely wouldn’t be able to go back to IE6. The tabs, while limited in options, are a great addition and make it much easier to browse the Web. I do have to admit that I am very impressed with how stable IE7 Beta 3 is which hopefully means they are preparing for the final release.