For the CSV : sometimes programs export data to "CSV", but they use a ; instead of a ,
Silly programs...that's not a CSV file then. =]
But I've just came across a program that exports to CVS seperated by ;
It was Microsoft SQL Server Management Studio.
I've exported a bunch of invoices, and to preserve the amounts, it uses a ; as separator.
And I didn't found a setting to change the exportsettings in it.
Even excel ha problems opening that CSV file. :-)
Perhaps you can provide a "default" separator, just a general application setting, and then it's up to us, the users, to change it according to the file we want to drop or open or import.
Just an idea. :-)