Any new release is bound to have some initial issues, no matter how thorough the testing.
I plan to wait, at least a bit.
I see no compelling reason to jump in compared to windows 7.
I see a few potential issues:
1. Upgrade in place may not work for all apps.
2. I do not much like the tiled interface and I don't know how well the free classic shell apps will work.
3. I don't know if you can go back to windows 7 after the upgrade. Is your w7 activation code negated.
4. I have the windows 7 3 license family pack which has only one activation key. . I can't change them all at once; I need to know how that will work.
5. I can't imagine that Microsoft will not try to extract some sort of future maintenance or support fee in the future.
6. For security reasons might they insist that all apps come from their app store?