Derrick Story's latest podcast is Adobe Engineer Pops the Hood on CS4:

Meet Winston Hendrickson, Sr. Director, Engineering, Digital Media, for Adobe.

During this chat in a conference room at Adobe headquarters, Winston and I talk about what's happening under the hood for Bridge, ACR, and Photoshop. He explains lots of goodies such as, the difference between the Lightroom and Bridge “databases,” the similarities between the Develop module in Lightroom and the sliders in ACR, improvements in Photoshop, and some great lesser-known features such as Camera Profiles. Terrific, informative interview.