Microsoft is really pushing for people to make sure their websites and apps are compatible with IE7. Apparently this is a real concern for a lot of people who relied on certain proprietary features, bugs, and quirks in IE6. I guess they figured they wouldn’t have to worry about future versions. (Hmm… I wonder where they got that idea?)
The fact of the matter is, I’m not worried. I tested my personal sites and the sites I’d built for work months ago, using the IE7 betas, and more recently with RC1. I made a couple of minor changes to some stylesheets, but that was about it.
Why? I’ve been writing standards-based code for years. I validate it from time to time, and I test to make sure it works in the latest versions of Firefox, Opera and Safari as well as IE. So the code was already portable.
Plus, anything new I’ve built since January has been designed with IE7 in mind from the beginning.
Most of the changes were to workarounds for IE6. Either stopping them from running on IE7 (if the bug was fixed), or keeping them running on IE7 (if it was done using a CSS hack).