RSS functionality - Yes, yes, yes. No longer will you think you have broken the page by clicking on a link to an RSS feed. Firefox already had stylesheets to explain what was going on with these pages, but now IE7 has gone a step better. The page is now displayed in a user-friendly format with explanation of what is going on and options to add the feed directly to IE7 feeds, or you can get a Bloglines plugin that will give you the option of one-click subscribe using that service instead. And the really neat bit is that you can then filter the feeds by keywords, or categories depending on the content of the feed - cool. RSS funcitonality built in like this will make a big difference to the take-up of RSS subscriptions. -- Website owners - make sure you have autodiscovery links in your
<head>tag where relevant.
Search engines in the browser toolbar - great - once again Firefox already had this with heaps of search plugins available from mycroft. IE7 has a list available you can choose from and you can build your own using a handy form.
Phishing filter - this can be turned on to warn you if a site you are visiting is not what it appears.
Improvements to print preview also.
So although there are now features in ie7 that I'm familiar with from Firefox, I still don't have all those extensions that I have come to rely on - colorzilla, measure-it, gmail notifier and more. So I won't be doing away with Firefox. But I can see a more jekyll & hyde approach to web browsing taking off for me.