Lyn here, from first time second time (thanks for the shout out citygirl!)
We are a two mom family who have both nursed our second child, now 5 months old. My wife carried and nursed our first and re-lactated for our second using the newman-goldfarb protocol after a little less than two years withiut nursing (birth control pills for 4-5 months, domperidone & herbs to stimulate milk production, lots and lots and lots of pumping for 4-6 weeks). I believe my wife mentioned reading of an MTF successfully lactating on this protocol. She collected links to the protocol we used and some other info in this post:http://firsttimesecondtime.blogspot....r-engines.html
If you click the "inducing lactation" tag, you'll get to a whole slew of other posts. We wrote about it a lot. I could imagine doing this would be quite meaningful as an MTF, but don't kid yourself, having two women nursing is not quite the wonderful fantasy world it sounds like (at least if one of you is hoping to induce lactation to actually produce milk -- in contrast to using a supplemental nurser -- but this sounds like what you are hoping for). There is a lot of work and a LOT of pumping involved, first for my wife before she was feeding (~ 5 times a day for many weeks) and now for me to maintain my supply for the feedings my wife covers (as the main source of food, we want to be careful not to risk my supply). Now that I'm back at work (3 days away from baby), this is less of an issue, since I'd be pumping anyway. There are also a lot of negotiations and logistics to work out, in terms of who feeds and who pumps when, and the baby has to learn to nurse from two people, likely with different "flow" and nipple/breast shape. Good communication between partners is an absolute must. Also essential is a commitment on the part of the pregnant/nursing partner for the non-gestational parent to nurse, which it sounds like you may have. It can be hard to step aside while someone else nurses your baby, even if that someone is your loving partner, and is also your baby's mother.
I hope I'm not sounding too discouraging. This has absolutely been a great thing for our family, and I could imagine it would be particularly nice for your partner, but you should not head in thinking it's a sure thing that she will be able to produce much milk, let alone a full supply, especially with the added challenge of being FTM (Gail is producing about 8 oz a day right now, she has been as high as 12 oz, and that's a pretty good response from what we can tell).
There are other good nursing options that stop short of a full induction protocol though. Comfort nursing is wonderful and delightfully low-pressure (I did some comfort nursing for our first) as are feedings with a supplemental nurser (like the Medela SNS or the Lact-Aid). Gail used the SNS for some early feedings, and I believe Lex here at MDC has used a Lact-Aid to supplement with her new baby (and they are also a two-nursing-mom family). And most of all, nursing is nice, but (IMHO) it is not the most important part of parenting. Far more important is the time you spend with your child. Nursing can guarantee that time, particularly with an infant, but it can also add pressure and tension, perhaps unnecessarily if there is already another source of milk, so it might also be good to strategize other ways for your partner to connect with your infant when the time comes, no matter what you decide in terms of feeding (e.g. taking substantial parental leave, babywearing, time alone with baby).
Good Luck! And by all means, freeze lots of sperm!