How to create CSS3 rounded corner elements for IE

Using techniques like this is slowing down the entire online industry. I would never ever clog my HTML to implement rounded corners in a browser released almost 4 years ago. No matter how many people are still using it. It just feels wrong.

If the entire industry would stop testing and developing for ancient browsers, I'm quite sure people will upgrade their browsers within a couple of months (I understand this is not possible from a business perspective). Companies that still rely on ActiveX components or other proprietary stuff, won't upgrade IE soon anyway, but they might install a browser like Firefox or Google Chrome for daily browsing.