There is always a risk when installing service, but many times staying where you are is an even greater risk. The initial release levels without any fixpaks have a substantial number of bugs. Personally, I would not use a new release of major software in production until one or two fixpaks were released.
If you install the Fixpak, make sure you read the directions carefully, and perform all post Fixpak operations that are required.
I like to use Powerquest Drive Image so I can completely backup and restore my C drive if necessary.