The most points you can ever have in 1 use year would be 3 times the number of points that you own. That would be from your current use year points, your prior use year that was banked, and your next use year which you could borrow. Banked points are only good for that 1 additional year. After that, they expire. Borrowed points are only good for the use year that you borrow them into and then they too will expire.
While true, I wanted to jump in with what just happened with my sister's points/reservations yesterday.
She was supposed to meet us ay WDW for a family reunion later this week. Unfortunately she lives on Long Island and her house was severely damaged by Sandy. She still has no power and is spending the days at a local library for warmth and the use the internet, etc. Then back to a freezing house at night.
She called MS yesterday to cancel her reservations because there's no way she can even think about leaving her house with all the work she needs done, such as new garage doors (blown out by the force of the water), new furnace and hot water heater, as well as carpet removal (water reached 5-6 feet inside their house, even taking out the fuse box). They have been able to get someone to pump the remaining water out, but are now worrying about mold on the sheetrock walls.
Anyway, MS told her since was 7 days until the reservation date, the best they could do was let her put her points (she had used 287 for the trip) into an RCI exchange. She just joined
DVC last year and this was to be her first trip as a member, and she was using 220 points banked from 2010 and the rest from 2011. She was understandably disappointed, but grateful that she could salvage anything from it.
About an hour later, she got a call from DVC, I don't know what level this new CM was. She told my sister, given the circumstances, they would let her have the 220 2010 points back banked until next year (she has a Dec UY) and the same with the remaining 2011 points.
They also refunded the park tickets she had purchased (which were special limited time event tickets offered for the W&D 1/2 Marathon, which we were to run).
So, since her next UY starts Dec 1, she'll have access to 220 points each from 2010, 2011, 2012 and another 220 she could borrow from 2013, not that she has to. She will have access to FOUR years worth of points!!
It's a shame, and not an everyday event, but DVC was so nice to her I wanted to mention it here that now she has SO many points the next couple of years she doesn't know what to do! I suggested she throw some my way, since we're still going, but will miss the reunion part of the trip, which is very disappointing.