OK, I am also a DVC member and am also donning my flame retardent suit.
1. DVC is great. DIS runs boards on DVC and you can check those out. Trading your points in for cruises is one of many ways you can use them.
2. When you buy in DVC, you purchase a set amount of points which you can use in many different ways during a one year period. You can borrow your points from your next use year and bank your points from one year to the next.
3. Many DVC member buy about 220-250 points. A DCL cruise takes at least 400 points depending on the time of year, accomodations, and number of persons traveling. Therefore, many DVC members need about two years of points to take a cruise.
4. The DIS boards for DVC claim the average price for a point is $10. I have no way of verifying that. Also, renting out your points is not as easy as some people make it sound.
5. I also can only go by my experience as to whether or not it's a good deal. We went on an Eastern 7 Day cruise in Jan 06. Total points for myself, DW, and DD-4 in a Cat 6. Total points were 491. Using the $10 number, that was $4,910. Price on DCL website was $4850. Not a signficant difference, even accounting for the $75 booking fee.
My overall opinion is that DVC is a great deal and being able to take a
Disney cruise, even once every two years, is just one of the options that makes it a great deal. But I suggest you visit the DIS boards for the DVC. It's as great a resource as the DCl boards with some really great moderators.
I will now go and put away my flame repellent suit.