If you haven't heard about it yet Googles next big update is called Caffeine
, it looks like it is going to be a biggie, here is some good info on it:
So far it looks to me (from using the 2nd link) they are putting even more weight on 'authority' websites as they started doing in the last update. So for microsites this could prove a bit of a killer
But having said that some of my mature websites look like they may take a bit of a battering as well (even though they are well estbalished, plenty of backlinks etc) but others look like they will improve in the SERPS, despite the fact they are of similar age, and I use all the same SEO
This update hasn't been rolled out yet so obviously I don't want to draw any conclusions, as I presume they are still working on it so these results will continue to change.
Essentially I think the fundamentals of ranking highly will stay the same (IE good content and quality inbounds wins out) but taking on the authority sites which have been around for many years will prove even more of a challenge!
Will have to wait and see though until Google have properly rolled out the changes and the 'webmaster blogs' have got their claws into it