Thanks for the link Dagmar and welcome to the forum.
A lot of us here have been using the public releases of both the beta and the release candidate of Win 7 Ultimate.
Kinda like the "ultimate test drive".
In my case the experience prompted me to purchase the retail version of Win 7 Home Premium (didn't really have a use for the extra features of the pro or ultimate versions).
With the RC approaching the end of it's life cycle this test drive may be the only way for folks that missed out on the beta/rc a chance to experience Win 7 prior to making a purchase.