What if Greedo Shot First?

Geek blog, io9 wonders what would have happened if Greedo got the first shot off in his encounter with Han Solo in the Cantina. Apparently, the green guy was on his way to take over the entire galaxy before Solo put an end to his rise through the Empire ranks…I feel like Boba Fett would have had something to say about this.

Any details left uncovered in this Star Wars alternate universe story?