For those of you who haven't upgraded to IE 7 yet, now you are another version behind. Microsoft officially took IE 8 out of beta.
The most touted feature seems to be InPrivate Browsing, which lets you browse the web without saving your history. A number of other new features are added in IE8 though, so check it out. IE 8 is also supposed to be better at identifying and blocking malware sites. That alone is worth the download.