I've noticed alot of people wondering if they'll be able to simply Upgrade from the RC to the Final Retail version once it goes live on October 22nd, 2009.
Short answer: NO..
You will have to do a Clean Install to go from the RC to the Final Retail Version.. An upgrade just won't work.. So my advice is to start creating backups of all your personal files now so once the Retail goes live your all set to go and won't need to spend hours burning stuff before installing..
Now, this is where you need to remember the little "Upgrade Media Trick" so you don't end up spending more money on Windows 7 than you really have to.. Refer to the following thread for the Guide on "How to perform a Clean Install using the Upgrade Media": Info regarding Upgrade Media..
This trick will allow you to purchase the Upgrade version of Windows 7 and still be able to perform a Clean Install.. Thus saving you a good chunk of money and still allowing you to enjoy the benefits of a Clean Install..
My apologies if this thread is a tad repetitive but I felt it was neccessary as the same questions are being asked over and over in various sections of the forum.. Hopefully this clears things up a bit..
Cheers for now!