IE 8 Beta 1 demonstrated some very interesting features like Web Slices but it was definately a beta. I uninstalled a few weeks ago because I found myself always in compat mode and I had issue debugging with Visual Studio 2008. The uninstall seemed to work fine---I didn't have any issues:-)
I downloaded Beta 2 yesterday. Debugging works fine with VS 2008 and in general IE 8 Beta 2 seems to work much much better so far. You can download IE 8 Beta 2 here. Here's a link to the developer center and more information at the IE developer team's blog.