I noticed a minor annoyance using Social Media Widget with WP Twenty Twelve theme.
When using 64x64 pixel icons, those with white background make the default image shadow (standard in the new theme) very evident. The small differences between icons (some are almost full size, while others have a more pronounced white border) are more apparent as well.
Could you please modify the widget's css in order not to show any border?
It would also be nice if users could decide how many rows and columns to display. At the moment the pull-down menu just shows two options: Auto and 1.