Virgin have also followed Jetstar's lead.
An interesting point of difference to Jetstar is that they are also handling requests via email and phone in addition to the airport, whereas Jetstar are only using their airport service desks.
Virgin's option is perhaps better for passengers booked on flights later in the week as they have the convenience of changing and confirming their bookings ahead of going to the airport. With Jetstar, you'll still have to hope their are seats later in the week. It will be interesting to see if JQ now follow DJ's lead.
But overall, good stuff by both airlines.