In earlier comments, I always cautioned people about IE9 and I just didn't trust them with actually creating a browser that works.

And while I agree with the article that IE9 is still very lacking, I also just went through making the application I'm working on IE9 compliant including rounded corners and shadows plus some CSS transformations. Here's the steps I had to do:

1) don't load IE specific CSS hacks

2) don't load IE specific JS hacks

3) ?

there was no step 3.

So if you are not using all the latest and greatest features in HTML5, but try using the essentials, you will get a very good experience while trying to make stuff work in IE9: The features it has seem to work correctly for a change and it has enough features to be useful in many webapps.

Of course it's still far away from being cutting-edge in feature support, but at least the usual crap of "try to open an existing website in a new IE version: see barely any page rendered until you add a ton of hacks" has gone.

Now, if IE9 would actually run on the (still) most-used operating system (Windows XP), I would be really happy as I could tell people to get a very good experience by just upgrading their browsers (as opposed to switching browser brand).