Just did a line by line comparison of the release notes from the version I had before the update, 2.36.108 and those for the new update, 2.42.40. Here's what I found:
1) Paragraph at the beginning has been added about "...multiple improvements to the USB listening experience...:
2) Sentence in the Modern Media Player section has been changed from “…bring popular content and your favorite stations front and center” to …bring popular content and your favorite music front and center”.
3) Section on Traffic-Based Routing Enhancement has been removed.
4) Section of Voice Command Improvements has a new sentence reading "Specify a number to call: You can now use voice commands to dial a specific phone number."
5) There were a few other places where some of the formatting and spacing changed but not the information.
I guess I'll add this to the Firmware 8.0 discussion lined to above for those who might want to wade through the nearly 4,000 posts there to find it. (Discussions that big really do need to be broken down into more manageable sub sections).