tedster - 5:36 am on Feb 6, 2010 (gmt 0)
My reason for bringing up recent backlinks is that Google does watch backlink trends. Long-time links can fade in their power under some situations. And even though you have more than the competition, having more links that are recent can make a difference, so getting some more BL activity still might help you. Link juice is not just a numbers game, or a PR game anymore.
I sure do see that your situation would be frustrating, especially if it goes on for a long while and the newly ranking sites are less relevant.
Just a guess here. There were several algo factors that Google mentioned in past patents (beginning with the historical factors patent in 2005) that sounded like good ideas, but rarely seemed to be in play. It seemed to me that these factors would require a lot of computing power to be practical. With Caffeine, Google may now have enough power to phase in some of those factors more prominently.
As I said, this is just a guess, but it is an idea that's been coming up for me more and more lately as I do SERP analysis.