Looks like there is a serious incompatibility with win8 and vmware fusion 3. As I was looking into this problem, it appears that vmware has released version 4 of fusion - hopefully that will fix the problem.
For what I can see, both parallels and virtualbox work well with windows 8 so if you're on fusion 3 and not willing to upgrade, you can use virtual box to play with win8
For what I can see, both parallels and virtualbox work well with windows 8 so if you're on fusion 3 and not willing to upgrade, you can use virtual box to play with win8