Changes: you need an official translation of your marriage certificate if it isn't issued by the Chinese / city's government.
No matter if it is authenticated by a Chinese embassy abroad.

What is the invite application letter that is now needed? Is this the same as getting an invitation letter from a Chinese citizen for a tourist visa? Seems silly that you'd need to be invited for a residence permit to a place where you already live (if renewing) by your own spouse...

Maybe the Chinese govt wants to make sure you've been treating her right, so she has to invite you every year! If you think you'll have problems with the invite letter, I suggest the Michael Kors or Coach store at Shuncheng.

The invitation letter just states who you intend to visit, contact information, and intended length of stay. Since it's basically a "visit family" permit it makes sense.

It doesn't have to be anything official looking. We usually just write it in a couple minutes while there if we forgot to do it.

Difference is we no longer write the letter, your chinese spouse needs to write the letter following a format they provide. Spouse must then sign and date letter.

This is the form letter that your spouse needs to copy with her/your own information.
[IMG]i62.tinypic.com/fa3e2v.jpg[/IMG]

This is the Application Visa form.
Front:
[IMG]i57.tinypic.com/or0x38.jpg[/IMG]
Back:
[IMG]i62.tinypic.com/2v29i15.jpg[/IMG]