Even if the score falls, I can't see it free-falling - the problem is that there's a bunch of people sitting in the 440's - so even if it falls a few points, you have a 12-month backlog of people sitting in that range that have waited for an ITA (where at most someone in the 450's had to wait a few months). Given that CIC seems to target 1500 people, my guess is you'll see it fall 1-2 points at a time if/when it goes below 450 - just due to the backlog of people there. I would also expect that the lower the score, the more people are that tier (simply because it takes fewer qualifications to get a lower score). I could see it falling to 440 over the next 12 months, but can't see it going below that.
FWIW, my CRS score is 430 and I took the PT from OINP - unless CIC changes things, I can't see the score getting to 430 in 2016. 445, that I could see, but I'd bet $20 we won't even see 440 in 2016 (barring CIC making a substantial change, going to 3 draws regularly, and even then I question it).