Concerning Mass Effect 3...
Mass Effect 3 will not win Game of the Year. The reason for this being, since 2006, no game has won Game of the Year without also being nominated for Studio of the Year. Although the GOTY winner and the SOTY winner have only ever matched up once (last year, with Skyrim and Bethesda winning both, respectively), you HAVE to be nominated for SOTY to win GOTY.
Mass Effect 3 will not win Best RPG. The reasons for this being: Since 2005, BioWare has been nominated five times for Best RPG for games they produced, of which they have won three (Mass Effect 2 in 2010, Dragon Age: Origins in 2009 and Mass Effect in 2007). They have lost twice, in 2011 when Dragon Age II lost to Skyrim... and in 2005 when Jade Empire lost to Word of Warcraft. This is the first time BioWare has gone up against a company they lost against, with Mass Effect 3 going up against Diablo III. It might not be enough by itself, but conventional wisdom favors the game that sold the most copies... which STILL doesn't favor Mass Effect 3. The only thing that anyone could use to justify as Best RPG win for Mass Effect 3 is that the first two games also won Best RPG, but my gut tells me that alone isn't enough.
But between 2004 and 2011, of the 38 games nominated for GOTY, only two have ever been completely shut out (Metal Gear Solid 3: Snake Eater in 2004 and Okami in 2006). Mass Effect 3 is bound to win something, so... JENNIFER HALE, COME ON DOWN!