I've been busy applying some new SEO principles to a few of our more important sites. The most recent is our real estate promotion website.
Of course these are not "new" SEO principles. These are just new insights I have had since studying various things on the importance of narrowly focusing your sites on more specific rather than general keywords.
Frankly I have always assumed that a healthy does of PPC was necessary to get the right kind of traffic. But I am changing my mind. I now have some definite targets in mind for about 10 different websites and three or four different blogs that I have simply not had time enough to properly focus.
We'll see if the "new" principles work. You can see a fairly detailed description of these principles at my online promotion site.