Some will certainly cheer such a change but others may dread it. There is a massive base of IE-only applications that exist around the world, from banking interfaces to media players to numerous pieces of software, all which bet on people most likely using (or willing to use) IE. For all of those, IE8 being the end means that inevitably they would need to move away from ActiveX and all other IE-backwards-compatible components. There's also the embedded application factor, where many programs use IE's engine to render content or perform other functions. It's a big change, and one that indicates Microsoft may be re-thinking their browser strategy altogether.
Of course, this is just speculation. There's a lot of good reasoning behind it, and Microsoft could potentially benefit greatly in doing so, but by the same token seek to lose a lot too. Part of their browser dominance originally focused around support for proprietary protocols and APIs, which gave them overwhelming advantages in many situations. If the software giant does ditch IE-based browsers, it'll represent a fundamental change in how many view the browser market. What's your take: should Microsoft dump IE in favor of something new?