This time around the upgrade were mostly for security and bug fixes:

Efiction Problem: Story count was counting only co-authored stories for some authors.
FIXED

Efiction Problem: Co-Author of a story not always showing up listed with the co-authored story.
FIXED

Efiction Problem: A search for an author would not bring up any stories they co-authored if they did not 'own' the story.
FIXED

Efiction Problem: General site statistics not accurate.
FIXED

Efiction Problem (Old): Open or Moderated series would not bring up only the authors stories, but would instead bring up the series owners stories.
FIXED

Efiction: Apostrophe's in the Bio cause a database failure error.
FIXED (I think)

Gallery Problem: Ability to upload and comment in the "Mature" category suddenly went away.
FIXED