Yeah, I skipped 1.5.2 and 1.5.3 and went straight to 1.5.4. I didn’t want to push out three versions within the span of two days (the others are tagged in Subversion if you really want them on their own).
1.5.2 fixes an issue with Cisco relays not liking packets sent from ports other than 67 and adds support for Oracle (thanks to Matthew Boedicker for making both of these possible). 1.5.3 makes PXE booting work when the client insists on using 4011 and you don’t want to set up another server (and it makes it easier to process client-vendor options). 1.5.4 makes upgrading from older versions a very simple process.
Full details, as always, are in the changelog.