Rules for adding new network drivers?

[Kaspar Brand <nbnet.08%velox.ch@localhost>]

Are there any particular rules when deciding if a new network driver
should be added to NetBSD? Specifically, I'm wondering about the
et driver (Agere ET1310/ET1301) originally written by Sepherosa Ziehau
for DragonFly [1] and ported to OpenBSD by Jonathan Gray [2].

Would this driver be considered for inclusion even when its current
vendor (LSI) now dubs it as a "legacy product"? [3]

I'm asking because I've actually ported it to NetBSD, since I recently
bought a board with this chip. Does it make sense to submit a patch
(needs some finishing touches), or is that just a waste of effort?
[Don't get me wrong: I'm willing to do the work, but I'd like to know
what the chances are that it gets accepted/included.]

Thanks for any guidance.

Kaspar

[1] http://leaf.dragonflybsd.org/cgi/web-man?command=et&section=4
[2] http://www.openbsd.org/cgi-bin/man.cgi?query=et&sektion=4
[3] http://www.lsi.com/networking_home/networking_products/legacy/index.html
    
http://www.lsi.com/networking_home/networking_products/legacy/ethernet/gigabit_ethernet_controllers/et1310/index.html