I just joined
DVC in March. Initially using points out side DCV seemed awesome even with the $95 exchange fee.
But then I found the DIS and read all my membership materials and realized it will not be as easy as they made it out to be, plus the number of points needed to stay at some of the places I want to go
That said, I used the 2009 points I received and a few 2010 points to book two week long vacations at DVC resorts for this year. (I own 180) And I had a ton to use for 2011. I know I didn't NEED to use them all, as I could have used 2010s in 2011 and banked 2011s, on and on and on.
But I really want to get to Europe, and a Med cruise has appealed to me for a while. So I looked at the
points charts and went for it. I think it is a great way to offset the cost of a expensive vacation. Other people do rent out points, but I just did not want to deal with that.
So we are doing a 7 night Med cruise and plan on spending a few days in Paris before and a few days in Barcelona after.
The vacation of my dreams

thanks to DVC is happening next year!
So while generally, using points outside of DVC is not the best idea, I feel there is no reason not to once in a while.
EDIT:It is two adults and we are staying in a cat 11b on the 7 night Med in August.