WooCommerce Simple Auctions will require you to customize the add/edit product template in order to add support for it. Right out of the box, we support Virtual/Downloadable/Simple/Grouped/Affiliate/External products. We have never claimed support for the Auction type of products, but we certainly do want to include it in the future by default, or have a replacement template file that you can use to drop in and use for the auction adding forms.
So, how do we do it *right now*? It would have to be custom programmed in the template, to add the form fields and hooks to save the data. This may be really easy, this may be really hard, we don’t know till we get in there and start working on it.
When can we do it? Jamie and I are slammed with Pro development, Free development, and working on v1.0.2 for release today, 1.1 for release within 2 weeks, and 1.2 for release within 4-5 weeks. We wouldn’t be able to work on this for you until after 1.2 is released.