Update: Realized I was giving JimmyZ and Arnsholt, much as I love 'em, a little too much credit. ;)
You seemed to have assumed that you've picked three key repos and that if some folk slowed commits to the main branches of these 3, then P6 dev was slowing and the missing contributors had slowed their contribution to P6. These assumptions are incorrect, as are others such as all commits and contributors being equal. Line count isn't going to be a better metric either. I recommend you visit the IRC channel #perl6 on freenode and ask questions; you'll get a much better picture of what's really going on.
At least 13 of the 14 folk you named remain active P6 contributors. (I'm excepting particle; he joined #moarvm a few weeks ago, but afaik he hasn't committed anything in a long while.) 11 of the 14 folk you named are highly active, currently contributing somehow near every day, 5 or more days a week, most for years. (The additional three exceptions are pmichaud, the P6 and Rakudo manager, who is occasionally committing and otherwise contributing but can't be said to be doing so most days; bacek, who contributes in fits and starts but hasn't done so for a few months afaik).
Of the top 50 contributors to the rakudo\rakudo repo, about 20 speak up on #perl6 pretty much every day and have landed commits to some P6 project repo (not just a personal P6 project) in 2013.
Of the bottom 50 rakudo\rakudo contributors, I recognize 15 of them as #perl 6 regulars in 2013, some making commits. (The numbers may well be higher than I recognize.)
The NQP repo includes several Parrot contributors (partly because NQP had a strong overlap with Parrot a few years ago) and Parrot dev has slowed tremendously. Even so, 26 of the 44 committers to the NQP repo since 2009 have NQP repo commits in 2013.
Ignoring whose contributing to what and how, Rakudo and NQP are both advancing rapidly, imo faster than in any previous period.
The main action in Rakudo/NQP land right now is getting the port to the JVM to the next level (ready for experiments with parallel processing, running on Android, etc.). I expect that to remain the focus in July, possibly August too. If you're trying to see where this Rakudo action is, follow branches in the Rakudo and NQP repos, or in forks folk have created, related to Rakudo/JVM. Note that since YAPC::NA, sorear, the creator of Niecza, has joined forces with jnthn on this port so now both of these two extraordinary hackers are working on Rakudo.
Others continue to work on the compiler ignoring the backend stuff. Watch the likes of timotimo, FROGGS, and newcomer ssutch.
Talking of timotimo and ssutch, note that these are both long time pythonistas that seems to have fallen in love with P6. It's interesting that the P6 project seems to be attracting contributors from outside the Perl world as much as from within. It's also interesting that ssutch was able to jump in to the compiler's guts and produce a working non-trivial patch in his first week of exposure to Perl 6.
Finally, MoarVM. The MoarVM repo was secret until 4 weeks ago. It has tripled the number of committers it has in 4 weeks, with several new contributors being well known uber hackers. (Chip Salzenberg has joined the channel!)
Here are the contributor graphs over time for the three repos you looked at: rakudo/rakudo, perl6/NQP, MoarVM/MoarVM. I agree they don't show a significant ramp up, but they don't show a significant ramp down either. The team is getting these pieces done, with or without help from others in the Perl community.
The above is focused on the three repos you picked. But there's lots more to P6 than those three repos. The module installer and ecosystem, key modules, testing components (including testsuite and japhb's workbench), rakudo debugger, Zavolaj FFI, documentation and so on are all important pieces. Check out the commits reported on #perl6; these are a good first approximation of the key P6 repos.
In summary, there have long been about 20-30 regulars, 50-70 occasionally returning irregulars, and a trickle of new folk, that are steadily building out Larry's vision.
Right now the vibe on #perl6 is very positive. The outlook for the rest of this year and 2014 is a joy to contemplate.
One last thing. Consider P5. I've heard that there are only 3 people in the world who deeply understand the guts of #p5p Perl 5: Nicholas Clark, Dave Mitchell, and Father Chrysostomos, and that they consider it a tough situation. Indeed, one of these three, Nicholas Clark, is now a regular on #perl6, and my understanding is that he sees P6 as being poised to deliver a technically excellent strategic way forward for P5 that sidesteps the deep problems of #p5p P5 without abandoning P5 (Pumpkin or otherwise). Talk of 25% improvement in the speed of the current p5 or Moose is easy; but just you wait until you dig in to the details...
Really, the best way to understand P6 is to visit the IRC channel #perl6 on freenode and hangout. Try it. I bet you'll like the folk even if you don't like the language!
In reply to Re^3: A "Perl-7" that I could actually USE right now