Windows 8.1—a free update to Windows 8**—will be available on 10/18.  
 
Is it safe to update, or should we ask individual Plugins/Software/Hardware manufacturer? I did not think 8.1 is like new OS, it should not have dramatic effect on everything. I am early adapter of everything- I install everything I see on the first day it available. What you think would happen if I install Win. 8.1? Thank you.           

Originally, when 8.1 Preview was released, RME reported some ASIO differences.
 
RME had to release new drivers to adapt. Either they were fixing something in their drivers or adapting to a Microsoft Change.
 
So I would say that 8.1 will not be a sure thing for everyone. It will depend on whether owners of your gear tried 8.1 Preview and reported issues if they exist.
 
Do you use ASIO?
 
Here's a link to the thread at RME.
http://www.rme-audio.de/forum/viewtopic.php?id=17980
 

Alot of reports came out about USB ports not working after the update,i'm not sure if it's  a safe idea.

Yes, I use ASIO and Presonus Studiolive. Also- many USB devices- like 10 at least...

vladasyn : many USB devices- like 10 at least
 
goto device manager and see that your USB ports are not set to turn off after 5min....> always on !