The second question I received from my SEO Questions & Topics: Reader Feedback Requested was;
Do you think google manually add sites in top 10 for competitive keywords?
If you want to know what I think, personally.... Well, I do not think Google manually adds sites into the SERPs based on it being competitive or not. I do think they adjust the algorithm to ensure the sites they want in the top 10 for certain keyword phrases are there. But I do not think they manually stick a site in.
Do they pull sites out? If they are "spammy" they will. If not, they may adjust the algorithm to knock them out.
All in all, I think for the most part, Google keeps it automatic and does not use manual means to have the "most relevant" results in the top 10.

Comments:
Teddie
11/04/2005 05:21 pm
I don't if you saw the eval.google.com stuff flying around a while ago, but that specifically indicated that for top ranked sites on popular searches they were meticulously checked. There was a supposedly authentic rating doc that did the rounds with instructions on how a site should be evaluated. http://www.searchbistro.com/index.php?/archives/19-Google-Secret-Lab,-Prelude.html