At the moment there is only “default” layout or temporary one (with Quick shortcuts) (see help/faq/toolbar-updates Asana Guide). One can persist temporary sets/filters/sorting/fields into “default” List View Layout. There are cases when there are several layouts useful in specific project for selected users or for many/all users.
I would suggest possibility to save custom layouts to More… menu for user herself (like Saved Reports with ability to name it), or share the saved layout with other users to reuse (if Adaptive Project Views suggestion is implemented that can automatically move out of More… menu.)