The pool on the left has a number of beluga whales in it, while the huge one on the right is home to dolphins. I've read somewhere before that the Shedd Aquarium has the largest indoor marine mammal pool on the planet, and so that is perhaps still true in 2009.
Mostly just major maintenance like re-lining the pools (necessary after close to 20 years of operation), and building a major new bank of offices on the roof above the seating area in the Oceanarium. Doesn't sound like any spectacular new exhibits will be added, despite the tens of millions of dollars that will be spent on the project.
Hopefully they will dust off the entirely artificial "conifer forest" that surrounds the public area--last time I visited it looked like someone needed to vacuum the cobwebs and dust in a major way!