Microsoft has not been serious about Internet Explorer since the days of Netscape. Back in those days, they set out to oust Netscape as the #1 browser. As you know, they succeeded in that mission.
With Microsoft’s recent announcement of the preview version of Internet Explorer 9, I believe they might be serious about the future of Internet Explorer. More specifically, they seem to be serious about the idea of advancing the web.
When IE8 was released, Microsoft had basically upgraded its rendering capability to CSS2 and increased the JavaScript performance. The rest of features did little to advance the web. It did bring IE up to the days of Firefox 2, a little dated, but not bad!
Enter Internet Explorer 9, with Firefox-grade JavaScript performance, SVG, HTML5 features and support for CSS3. It is currently in development, but I see this as the most significant upgrade to IE since IE6.
Finally, webmasters around the world will be able to take a serious look at HTML5, SVG and the latest CSS3 specification. We have all been held in a timewarp of website development capabilities even though the alternative browser have had these modern features for years.
This by no means is an endorsement for Internet Explorer (since I use Firefox, Chrome and Safari). Though, I am definitely looking forward to CSS3, SVG and dumping Flash for video streaming on the websites I develop after IE9 is released. The unknown is how long it will take to get existing IE6, IE7 and IE8 users to upgrade. Kudos Microsoft for starting to take IE seriously again!