MGM Mirage Profit Up on Las Vegas Tourism  NEW YORK (Reuters) - Casino operator MGM Mirage &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MGG.N target=/stocks/quickinfo/fullquote"&gt;MGG.N&lt;/A&gt; on  Wednesday reported higher third-quarter earnings as tourism and  gambling at its Las Vegas resorts boomed.