You're better off with hotels a few blocks north in the prime downtown area. It's a BIG difference of skeeziness that a few blocks make. But, really, the convention center area with the Staples Center and the new L.A. Live center (that might be finished by then) is pretty safe. There's just sort of a no-man's land all around it ... and you don't want to head south or east. Much nicer hotels are a few blocks to the north, in the main downtown area of City Hall, the State and Federal Courts, the Walt Disney Concert Hall, Dorothy Chandler Pavilion, etc. Ghost Town on the weekends, but perfectly comfortable and safe-feeling.
As an Angelino, I must tell you that downtown is one of the least interesting parts of our city. Bleh.
I'm still not positive I'm going to the convention, but with it being in L.A. - I guess I'll find it hard to resist.