To make IE7, just add these up:
Internet Explorer 6
+ rss reader
+ shiney interface
+ PNG transparency
+ a couple of CSS fixes
+ phishing filter
It still has the same security issues (since it's really just a modification of IE6's rendering engine and still supports ActiveX) and falls *far* behind all the other browsers in supporting CSS (Firefox, Opera, Safari and Konqueror all trounce it).
If you're wondering about it compared to Firefox... Firefox still has the advantages of a better rendering engine, better security, plentiful (and damn handy) extensions, faster download, faster install (with no reboot), etc. Plus the whole open source, cross-platform (Windows, *nix, Mac) and being able to carry it portably with Firefox Portable.