Reserved IPs are as defined by various RFCs and include: (a) 127.0.0.* (b) 192.168.*.* (c) 10.*.*.* and (d) 172.16.0.0/12.
Support for DMARC (Domain-based Message Authentication, Reporting, and Conformance) has been added.
DMARC defines a scalable mechanism by which a mail sending organization can express, using the Domain Name System, domain level policies and preferences for message validation, disposition, and reporting, and a mail receiving organization can use those policies and preferences to improve mail handling.
The DMARC specification and full details about what it does and how it works can be found here:
 The SPF cache file now caches a domain's actual SPF policy record taken from DNS rather than the final result of SPF processing.
Your old file can not be migrated and so was renamed old in case there are settings in there you need to refer to.  Domain Keys has been deprecated (see below).
As a result the content filter action to sign messages with Domain Keys will be ignored.
If you were using this action in any of your rules you may want to either change them to sign with DKIM instead or delete them if they are no longer needed.
 The two options to hide local IP addresses and local LAN IP addresses when processing message headers have been deprecated and removed from Ctrl+O | Preferences | Headers.
They have now been replaced by a single option which hides reserved IP addresses.