Set Default Browser From the Command Line
This can be done using the tool: defaultbrowser
Works like a charm.
With no arguments lists your browsers and marks the one being the default.
$ defaultbrowser
iterm2
* chrome
firefoxdeveloperedition
safari
vlc
evernote
netnewswire
Setting it is simply by providing an argument, matching the list
$ defaultbrowser chrome
Do note that this displays a GUI dialog,
Currently there is no fix for this minor inexpediency, the dialog can be expedited with a swift ⇥ (tab) followed by a ␣ (space).
this keyboard navigation seems to have been disabled in newer updates to MacOS 