Start R with --save?

I would vote for a preference option, because I actually like the  
opposite behavior (--no-save) by default :-)

Ok, now implemented in 3317. For now there is no UI for it, so you  
can set it only from the shell, e.g.:

defaults write org.R-project.R save.on.exit -string no

Possible values are (strings, case-sensitive): yes/no/ask. Anything  
other than yes/no is treated as "ask". The setting applies only to  
the console, it has no effect on editor windows.

Cheers,
Simon