Google’s (GOOG) fourth-quarter profit plunged about 68% -- to $5.10 per share -- but the company beat Wall Street’s expectations. That’s not a wry comment on the sour mood of investors - Google’s business plan showed continued strength and the company appears well positioned to weather the economic downturn. Google’s net income skidded to $382 million or $1.21 a share from $1.21 billion or $3.79 a share for the same period a year ago. The company blamed the lower earnings on charges on its investments in Time Warner’s (TWX) AOL unit and Clearwire (CLWR) operator of a wireless broadband network. It ...