Hi,
It's actually already possible for custom fields of the table "product".
We worked on that in the past few releases.
When you edit a product in the backend, if you go at the bottom of the page, you'll find a green area where you can click on the "add new block" button to add a new section to the interface.
You can also drag & drop all the blocks of the interface on their title.
And you can also drag & drop each custom field between them, but also from one block to another on their label. And it's actually not limited to custom fields but also to the normal fields of the interface too.
You can read about all this here:
www.hikashop.com/home/blog/481-hikashop-4-5-1.html#prod