Microsoft, Google Square Off in Search Arena  SEATTLE/SAN FRANCISCO (Reuters) - As Microsoft Corp.  &lt;A HREF="http://www.reuters.co.uk/financeQuoteLookup.jhtml?ticker=MSFT.O qtype=sym infotype=info qcat=news"&gt;MSFT.O&lt;/A&gt; prepares to launch its own Web search engine to take  on Google Inc. &lt;A HREF="http://www.reuters.co.uk/financeQuoteLookup.jhtml?ticker=GOOG.O qtype=sym infotype=info qcat=news"&gt;GOOG.O&lt;/A&gt;, industry watchers are already  speculating over which rival will be left standing in the  high-stakes competition.