Can someone with experience on Google Compute Engine try out running DragonFly on it?  There's FreeBSD instructions, so it might work.
bycn82's rewrite of IPFW2 is available as a git branch to try out; he's posted the link.  Please try, especially if you are still working with the original ipfw. (note: remember, 'ipfw' in DragonFly is what was called 'ipfw2' years and years ago because it was a replacement of the original 'ipfw' in FreeBSD.  It was called ipfw2 but referenced as ipfw so that the same commands worked.  Technically, this branch bycn82 is working on would be ipfw3, but he keeps referring to it as ipfw2.  Confused?  Good.)
If you look at your local DragonFly mirror, you'll see ISO and IMG versions of DragonFly 4.0.0RC3.  Please run, break, and report. (Check the iso-images directory.)
Markus Pfeiffer has imported FreeBSD's if_lagg to DragonFly.  It's for talking LACP over multiple network ports, so that the traffic from those multiple ports can be aggregated - if what's on the other end generally understands LACP.  (Failover mode may not count.)  Please test if you have that sort of surfeit of network ports.
I've branched DragonFly 3.8, and tagged a release candidate.  Please try the release candidate if you can.  I have links in my post to users@/kernel@.  Don't forget the remaining issues!  Planned release date is June 4th.
Sascha Wildner has updated ral(4) with support for RT2700/2800/3090 chipsets.  If you have one of these, please try it out - these are untested.
I've wanted more support for virtualized DragonFly systems.  Sascha Wildner put together an experimental balloon memory driver to test out, and I ran it on two virtual machines separately, one with it loaded and one without, on the same host system.  The problem is, I can't tell what it does.  The two machine reported almost the exact same RAM usage during a buildworld. Any VMWare/virtualization experts out there able to tell me what needs to be tested to verify this?
I have a list of commits I've saved between the various BSDs of licenses getting corrected to the 2-clause BSD license; that would definitely be a good cross-BSD project to sync.
Sepherosa Ziehau has an IPv6 patch for you to try.  What's it do?  I think it improves performance under multiple streams of traffic, but that's from looking at the code and totally guessing.
DragonFly has moved from the old USB stack to USB4BSD by default.  That means:
  • If you are already using USB4BSD, you will want to remove WANT_USB4BSD from your kernel config.
  • If you have trouble, switch back to the old USB.
  • There's some drivers that are not yet converted; help with them would be appreciated.  
  • A full kernel/world build and 'make upgrade' will be needed in either case.
Sascha Wildner's announcement email has all the gory details, including the kernel config changes to move back to the old USB setup.  This is of course in master; 3.6 users are unaffected.
If you want to test out the latest (20131218) update to ACPICA, Sepherosa Ziehau's got a patch for you.  This will be good for anyone who wants to use less electricity.  (updated to reflect this doesn't enable deeper C-states as I thought it did.)