The main changes were switching from the socket 1156 to 1155 CPUs on the $800 and $1200 computers. For the $1800 computer and above we are sticking with recommending socket 1366 until socket 2011 comes out later this year. Going with a socket 1155 motherboard and Core i7 2600K is definitely an option for higher end systems.
We also doubled the recommended amount of RAM on the $1200 and up computers. This is made possible by low RAM prices. Windows 7 64bit loves RAM and the more you give it the smoother your system will run.
The other changes were mainly price updates and a few replacements of discontinued parts.
You can find the main parts list page here.