OK. After much observation and discussion with a random collection of other part-time Mac Developers, I have come up with the following information:
1- The issue of "Not Responding" processes can happen to ANY process.
Just Recently, I have had it occur with both Mail and "softwareupdated" as well as the infamous "geod."
2- The problem is clearly a product of Yosemite (I'm running 10.10.1) -- what is unclear is WHICH part of Yosemite is the cause.
i.e. it did not happen prior to Yosemite. (Out of date - not verified to run on Yosemite - 3rd-party software is a separate problem.
EtreCheck can help spot them.)
3- The trigger appears to be "ANY connectivity issue." If an application (any program or OSX Daemon) is running when a communications "glitch" occurs,
there is a 50-50 chance that application will become "Not Responding."
4- In Unix(tm) terminology, that application has become "wedged." -- it is waiting for some response from something, which will never happen,
eventually it will show up in Activity Monitor as "Not Responding."
5- If you look at the "info" -- the "I" button at the top left of Activity Monitor for any non-responding process, you will discover that the "Recent hangs"
count is always greater than zero.
6- You can always use the "X" button in Activity Monitor to Force Quit the "Not Responding" process.
7- So far we have found nothing which reliably prevents a "Non Responding" process from happening.
The potential causes appear to be many and varied. Any given "fix" will seem to work for a period of time and then fail again -- especially with "geod."
8- A number of bugs exist which "might" impact this problem. We won't know until 10.10.2 (or later) is released if such "Not Responding" processes simply "go away." In other words, in the short run, at least, this is an issue we will simply have to live with. 😟