Evernote's Mac client + Marked or similar: basically just setting ~/Documents/Evernote Selection.md to the content text of current note converted from HTML to Markdown.
First,
$ [sudo] pip install html2text MacFSEvents
Then launch it and enjoy.
P.S. guess what, ⌘S works in Evernote.
One step closer -- I ran the script locally by just doing python evernote_selection.py and everything seemed to work as expected. But for whatever reason, the script won't work automatically unless I drop to terminal and run it manually.
I've put the script in /usr/local/bin which is in my $PATH, just not happening automatically for whatever reason. Any thoughts?