I can't tell for sure, but I think I got on an RCI waitlist in early November last year (2009) and got confirmation for the last week of October 2010 in the middle of January 2010. (The confirmation and reservation info I know, I just can't tell exactly when I made the request.)
I, too, was unhappy to feel so uncertain about when I'd get a week or even if I'd get one. I don't think I'd do it again, to be honest. I don't know what timeframe you're giving, but I know I told them I could do any week within a 3 *month* period. If you're looking for a more specific time than that, you might want to try a different route.
One consideration might be how many properties are available in St. Lucia. I had only one option in London, which I'm sure cut the probability down significantly that I'd get anything. (The week I got is the week the kids are out of school, which may explain why it became available.)
I think I'd try MS some more -- maybe you can find someone there who's been doing the RCI swap thing for a while and can give you some idea of how likely you will be to get anything, as well as how long the "line" for DVC-->St Lucia generally gets. If the odds are decent that you'll get what you want if you're the first in line, you might try it now. Alternatively, even six months of you waiting to put your points in might give you enough "wiggle" room to get a one-year anniversary trip out of RCI, if the honeymoon trip doesn't come through fast enough. Good luck.
