(Disclaimer: IANAL.) Some changes of note:
* Rules on Covered transactions now apply to transactions/employment/etc with those who have been trustees/executives/"key employees" at any time in the prior 12 months. (Such transactions may still be approved by the Board, following procedure.)
* This was added: "In order to approve a Covered Transaction, the Board must conclude that: [...] the Covered Transaction does not involve the Foundation hiring as an employee or contractor an individual who had been a Wikimedia Foundation Trustee within the preceding 6 months." That seems ... overly specific. It doesn't apply any of the other normal rules on CoIs to recent trustees, like those dealing with other transactions/agreements/contracts, etc.
* Situations with "perceived conflict of interest" ("in which the interests of a Covered Person may be seen as competing or at odds with the interests of the Foundation") are no longer covered by the policy.
* Re when the Board is determining whether a transaction counts as self-dealing/etc, a part of the procedure was changed from "[The Board] shall consult with the Foundation’s legal advisor as necessary" to "The Board may consult legal counsel and other outside advisors as part of its determination.", which seems to make it more optional?
* The policy goes into somewhat more detail on the procedure for assessment of CoIs, and dealing with violations of the policy.
I really wish that the WMF itself could provide summaries of changes to its rules. Unfortunately, it often doesn't, and even when it does, it often leaves out critical modifications (e.g. certain things in the last bylaws changes), requiring volunteer effort to determine what the WMF is doing.
-- Yair Rand