(editing: oops Pat, just realized you were talking about Silversea, not Regent so ignore. Sorry! <img border="0" alt="[c]" title="" src="graemlins/c.gif" /> )
Pat,
Out of curiosity which segments of the WC are sold out? Last I heard people had to do a minimum of 3 segments. The Voyager is such a great ship, I don't think there is a bad cabin on it so not being able to choose your cabin wouldn't concern me too much (unless you are prone to motion sickness and need something low and midship for that reason). We've had guarantee on that ship, so have Joanna & Tony (and I'm sure others as well)...so far it's worked out for us with good cabin locations.
The WC sells out quick, it really is that special with many events and excursions included unlike a normal cruise.