This is great news. Pkgng is very easy to use and achieves a very good combination of binary packages and the FreeBSD ports tree when you want to compile stuff yourself. Which happens more often than expected admittedly.
(pkgsrc is the NetBSD version of FreeBSD ports, but its always been portable to other systems).
I have generally used source not packages for non NetBSD platforms, other than when I tried out SmartOS and it is all set up. If you have a chunk of disk space, a fast computer and some time you can compile them yourself, and if someone wants to support osx 64 bit that would be great.
However this project could really use some nice webpages and instructions to promote it. It seems like most Mac devs have never heard of it. And much of the info is pretty minimal and seems like it assumes you understand NetBSD packaging.