There are many fine points of SEO I never see people comment on. I find tons of SEO 101 and 202 information. I am interested in some of the advanced topics and issues.
In my opinion, there's really no such thing as advanced SEO topics, as they are often techniques which would be considered "spamming" of the engines.
Most of us here purposely don't optimize sites for highly competitive keyword phrases because we have found that you're often competing against tons of spammers.
We've found that if you concentrate on keyword research, and optimize for two and three word phrases that are highly relevant to your business, you may not get as much traffic as a one-word keyword, but you will get much more highly targeted traffic and thus higher conversions to sales rates.
That said, I believe the folks over at WebmasterWorld discuss what you might call "advanced" SEO topics.