After some thought, my friends and I declared that Wash was the best candidate for m-preg we'd ever seen. Because I can imagine Zoe pregnant easily enough (and omg Zoe hart) but I can imagine Wash pregnant just that much easier, and it really wouldn't get in the way of his general lifestyle. (Can you imagine him complaining about having swollen feet? I can. ^^; )
Mostly only funny if you're a Firefly fan but, hah! I am not an mpreg fan by any means but I want to see fic come of this. Anyone? XD
ETA: Serenity movie spoilers in comments. Sorry. ._.