Last week, Vulture Blog posted its "'Umbrella' Watch," a list of the top 5 contenders for this year's Summer Jam. Whoops, Vulture Blog, you missed one. Nas (feat. Keri Hilson), "Hero." (via Nah Right) I think Nas was right to make the video dull and unimaginative, with your regulation sports cars and non-partisan ski masks (we're not going to take ...