Tecmo has finally launched Ryu's ninjtastic site. The official Ninja Gaiden Sigma site sports heavy use of Flash, touting screenshots, trailers, and wallpapers among other things.
They also assure visitors a demo is available on the PlayStation Store (as if anyone visiting the site didn't already know that!). Unfortunately, you'll need to be 18 to enter (if you lie Ryu will come to your house and throw a ninja star in your eye).
Ninja Gaiden Sigma will be available exclusively for PlayStation 3 on July 3rd.