Most of the changes are minimal tweaks and minor additions. The most significant addition is a new example project that provides a model for Max externals that link dynamically to other libraries (DLLs, dylibs, frameworks). The relevant information on this project is in a "ReadMe.txt" file in the projects folder, which you can browse here: https://github.com/Cycling74/max6-sdk/tree/master/examples/advanced/dllexample
Delayloading dependent Windows DLLs an external needs/wants can be helpful to handle situations when/if the dependent DLL isn’t installed to allow for a graceful degradation of the external rather than a complete failure. I use this method for some features on dp.kinect.
When you freeze a device it should automatically copy your external.
The one caveat is the (somewhat rare) case where you have an external DLL dependency: the external will be copied automatically but the DLL will not be as Max (at least at this time) does not know about the linker dependency.
1. Assuming you do not have the DLL dependency issue, freezing will do the job.
2. You can include both .mxo (mac) and .mxe and .mxe64 (windows) in the same package for a single cross-platform distribution.