Win8: definitely not. It is probably great for tablets. For laptops with touch screens, it will depend on what the machine gets used for (in my case, it would be next to useless). For desktops, unless all one does is surf the web or make an occasional Word doc, it will be considerably less productive (in my case, totally useless). Touch screens aren't very ergonomic, especially for heavy users (even a touch pad is more practical for me and I hate touchpads). In my case, using a touch screen more than very occasionally would be painful due to adhesive capsulitis, aka frozen shoulder (maybe I can sue Microsnot for violation of the ADA?). There is no way I will ever use Win8 unless I get a tablet (and that is unlikely anytime soon). Even if I do get a tablet, I'll probably run Android just to snub my nose at Microsnot.
Win9 is still an unknown entity. At the rate Microsnot (or, in this case, Micro$$$oft) is pushing for an Applesque walled garden with cloud computing and renting software instead of selling it, I'll probably won't use Win9 either, preferring to run Win7 to its last dying gasp. Of course, if Win8 spectacularly flops for anything other than tablets (like I expect it will), Microsnot may take the hint and return productivity (default desktop, infinitely resizeable windows, etc.) to Win9. It's just too early to say.
If Micro$$$oft continues on its present path, I can only hope that someone will develop an OS that will be directly compatible with productivity programs that currently run on Windows.