Innodisk has launched the EGPL-T101 M.2 network card. It features a Marvell AQtion controller, supports 10GbE, and uses a small daugterboard for port connectivity. The card is aimed at the embedded and industrial markets, but no doubt someone in the SFF world will find a way to put it to interesting use.
One of the most difficult aspects of SFF builds is the lack of expansion for upgrades such as a faster network cards, capture cards, or additional M.2 slots. The majority of the time, SFF builders need to rely on external USB powered adapters and expansion. However, there is a small but growing market for M.2 solutions as an M.2 slot can support up to PCI Express 4.0 x 4. Time will tell how useful these style cards become for everyday users, but at least there is a growth in options.
Pricing is not yet set, but expect to pay the usual SFF tax.
Here is a link to the product page.