Whenever I add a site to my multisite installation, I need to manually tick all of the new tables, but it's always the same stuff, so why not automate it?
I suggest letting people choose between "include" and "exclude" mode. "Include" mode is where tables must be ticked to be backed up, which is what happens now. "Exclude" mode is where tables are backed up UNLESS they are ticked.
Additionally, it'll be nice to include "select all" and "unselect all" buttons/links to choose tables faster in any mode.
What do you say?