Cattle (unless you book the full fare business class, although why you'd do that with Jetstar when TK offers many better carriers or their own metal is beyond me).
However, IME you can select extra legroom seats free of charge (currently have row 10 seats booked for a trip in March and April). Not sure what else to expect as the only other time I did this I was on TG going over and, due to a schedule change, MH coming back.
