Chris,
 
I guess you're mostly asking what are the substantive changes, but it appears there are numerous changes in wording and style as well.  As an exercise, I located a copy of the 2007 ruling from Google's Cache.  I then loaded the 2007 rev into Word, and then the 2009 rev, and did a Compare between the two.  Word found many changes -- too many for me to sort out style versus substance.
 
(Suggestion: keep every version of something as important as an Administrative Ruling online forever.  It's kind of like losing legislative history otherwise.)
 
This appears to be a key substantive change:
 
Old:

“Bulk e-mail” in this context means the transmission of an e-mail message within a short time frame to more than a small set of recipients who may not have elected voluntarily to receive the e-mail. “Short time frame” means an interval spanning as long as 2 days. “Small set of recipients” means the size of individual-recipient address lists (To, CC, BCC fields) typical of most e-mails in common use, ranging from 1, to a few, to as many as may be involved in a large committee or work group (~20-30). Use of mailing lists and listservs to which recipients may voluntarily opt in and opt out is encouraged, and this type of e-mail distribution is not included in the meaning of “bulk e-mail” in this document.

New:
 

III. Definitions

A.    Bulk e-mail: The transmission of an identical or substantially identical e-mail message within a 48 hour period from an internal user to more than 10 other internal users who have not elected to receive such e-mail.

 

/rich

On Wed, May 6, 2009 at 6:41 PM, Chris Wolf <[log in to unmask]> wrote:
And no one could take a little time to summarize the changes for us? Not
even a clue? Shouldn't the very first FAQ be "What the heck changed in the
May 2009 update?"

I absolutely hate this kind of correspondence when it comes from my bank or
my cable company. It's just as worthless when it comes from the University.

-----Original Message-----
From: Dave Gift, Vice Provost, Libraries, Computing and Technology
[mailto:[log in to unmask]]
Sent: Wednesday, May 06, 2009 5:09 PM
To: MSU Community
Subject: Appropriate use of MSU e-mail services

This message is sent to notify everyone with a MSU NetID of a revision of
the Administrative Ruling regarding appropriate use of MSU e-mail services.
This revision replaces and further clarifies an earlier Administrative
Ruling originally posted in November 2004 and updated in September 2007.

The Administrative Ruling is posted at:
http://lct.msu.edu/guidelines-policies/appropriate-use-of-msu-email.html
It is accompanied there by a related FAQ.