For this month, we want to add filters on products listing pages ( to be able to filters products by price, by characteristics, by custom fields, etc ). We are also looking at adding a new type of custom fields for order items so that you can ask questions to the user for each product in his cart.
We also would like to add multi tax capability in HikaShop.
We don't have decided yet what will be next after all that but we have a big payment and shipping gateways list to integrate with, as well as a big list of little options to add here and there.