Pardon my language, but... #*$! yes.
What I'd really like to see is the option to turn those "improvements" off on an individual basis. I think synonyms and stems could be useful, but Google's a lot more prone to screwing up the similar phrases part (their own example is perfect: someone searching for [floral shops] isn't necessarily looking for delivery).
Aside: I like how a verbatim search for [run] has more results than a standard search for the same word.