I don't usually like looking at the stats from the first round games because there are so many opposing factors and blips that can screw them up. For instance, looking at the last 4 years, 2011's first round had by far the most games decided by 5 or fewer points, and yet it overall had the largest winning margin in games and also the lowest winning seed average (the expected teams won more often). But when you have teams winning games by 65, 45, and 40 points, the stats get skewed somewhat.
This year's first round has been fairly average overall, but the one factor that is a little off the norm is the average winning margin, which is 4.1 less than last year and is the lowest for the last four years. This is mainly because of the high number of games won by 10 points or less. which is 12. This year has been a little wilder than last year on the side of more modest seeds advancing to the second round, but the difference isn't huge and one region has gone exactly as seeded.
Stats for 1st round are:
Year ............ Avg Winning margin ................. Average winning seed
2012 ............. 17.0 ............................................... 5.13
2011 .............. 21.1 ............................................... 4.91
2010 ............ 20.3 ................................................ 5.25
2009 ............ 19.4 ............................................... 5.35
There is not necessarily any correlation between a higher average winning margin and a lower average winning seed (the favorites winning more often) but it sometimes works out that way. But again, one 65 point win can blow away 6 close scores, and if you throw out the four biggest winning margins for each year, the averages get closer.