Here are the sources for the science center expansion announced in 2008.  Dr. Jackson also mentioned an expansion to the Hirsch Observatory. Follow the links for information released by the administration.

Polytechnic article on center
Initial announcement by Dr. Jackson at "State of the Institute" address.
2008 Town Meeting announcement

Here are the relevant slides (click to make larger).

Also, here are the plans for the ridiculous 2009 landscaping project: