mine are just coming into the flowering stage at the moment i was thinking beetroot was going to be my replacement or savoy cabbages but am not totally decided yet on what to put in look to wards the winter crops for inspiration.
It may be good to think about crop rotation too - planting different types of crops over a three year cycle - which reduces risks of various disease / nutrition problems that can occur if you grow same crops in same place all the time.
things that are good to plant now include
almost all the brassicas, such as cauli, cabbage, brocolli, kale, chinese cabbage, calvano nero, radish etc
leeks, silverbeet, summer spinach, summer lettuce, fennel, celery, beetroot, mesculn, endives and chicories, and i'm sure many others. i like to plant a few spring onions so they are ready to eat over the winter, for stirfries etc.
my knowledge is biased to the canterbury region, but it is a good indication of the plants we are selling for home gardeners currently.
my only question is if you have a crop rotation going on, which may influience your choice.
We plan to plant an early crop of broad beans soon, these will improve the soil by fixing nitrogen (actually they feed some bacteria in their roots, and they fix the nitrogen). They are easy to grow and taste great, particularly if you pick them young, chop up some mint and put them over some pasta with a bit of crumbled feta and olive oil. Yum