The Upgrade Path (http://cookbook.fortinet.com/sysadmins-notebook/supported-upgrade-paths-fortios/3/) for FortiOS was updated and the FortiOS 5.4.2 Release Notes (http://docs.fortinet.com/d/fortios-5.4.2-release-notes) was also updated.
The Upgrade Path now says that you can upgrade from 5.2.7, 5.2.8, 5.2.9, or 5.4.1 directly to 5.4.2. However, it only shows 5.4.0 upgrading to 5.4.1, not 5.4.2, so maybe that's supposed to be a two step upgrade.
The Release Notes don't match the Upgrade Path. The Release Notes now state: "supports upgrading from version 5.4.0 and later and 5.2.8 and later." That implies you can upgrade directly to 5.4.2 from 5.4.0 and can't upgrade directly from 5.2.7 -- both disagreeing with the Upgrade Path.
The Release Notes still don't say which versions of FortiAnalyzer 5.4.2 FortiGates are compatible with. The link to http://docs.fortinet.com/d/fortianalyzer-compatibility only refers to 5.4.1 or earlier.
The Release Notes do say that 5.4.2 should be compatible with FortiClient 5.4.1 and FortiAP 5.4.1.
Looks like 5.4.2 firmware has not been released (yet?) for various hardware beyond the 60/61E, like the 90E, 2000E, 2500E, and perhaps some others.
Anybody tried out 5.4.2 yet? How did it go?