over the last few years SEO has evolved with new seo tricks produced like alt tags, or keyword density or relevant backlink count or internal linking and anchor text etc are there any new developments in seo?
2008 guess not now. If you do notice, all these tricks came out after Google decides to penalize on some factors. So now we are simply waiting for Google's next move and new tricks will be out. Any way SEO is a waiting game, be patient and just do your normal routine of SEO. Results come with efforts.
I think google will not be able to find out if you do not sell links so often. And I think we should never disclose our website urls that are selling links to the public....