While I agree that Google seems to be getting less relavante with a lot of the results from my searches, I don't think "this is it" is a good string to search for. Anytime I have used the word "and" in a search string, I am told in the results "and" is a common word and won't be used in the search... it seems to me that "this", "is", and "it" are all pretty commonly used too, so maybe Google's engine is confused on exactly what to show you, even if you do select the "exact phrase" option.
But, there have been several times in the last couple months where I have wanted to show somebody something that I didn't bother to bookmark and that I was easily able to find over and over in Google just by doing a search. Next time I looked for it nothing close come up again. I know I searched the exact terms again because FireFox's cache showed me it as an autocomplete in the field. Couldn't for the life of me fine any of it on Google. Went to Yahoo which I hadn't don in ages... first search, first page listed. Go figure.
