Perl:

   join "\n", grep { $_ } map { $_->description } @myList;

Or

   join "\n", grep /./, map { $_->description } @myList;

Ruby:

   myList.collect { |f| f.description }.select { |d| d != "" }.join("\n")

Python:

   descriptions = (f.description() for f in mylist)

Or if we'd like to constrain ourselves to one method `FooClass.description()`

   descriptions = map(FooClass.description, mylist) # `map` returns an iterator in py3k

   "\n".join(filter(None, descriptions))   # `None` means `lambda x: x` here

Or if you don't like `filter()`

   "\n".join(d for d in descriptions if d) 

Or if `description()` is a side-effect-free method then It should be a property:

   "\n".join(f.description for f in mylist if f.description)

At the end of the day new features doesn't matter due to most .NET-shops use old C# versions and It will not change any time soon.