I just got an email and this is the quote of what they said:
The Subscription extension does not integrate with the WishList Member. If you wish to sell memberships with recurring subscription fees then you would actually want the Groups Extension + Groups plugin: http://www.woothemes.com/products/groups-woocommerce/
There are a few Payment Gateway options for selling subscriptions with recurring fees which you can read more about here: http://docs.woothemes.com/document/payment-gateways/
What do you think?