I agree, from the utilitarian point of view serrations are great, but sharpening them is extremely hard from what I have heard. But I do not use my balisongs for cutting anything (well, once in a while I'll use 'em) I have my Spyderco Lum tanto Ti plain edge or my LCC DA on my right side, and a BM 942 first production plain edge on my left hand (had to switch the clip for LH).
Hmmm, what pattern? How about all small teeth, all the same size, no real pattern, they would go around every sharp edge. Manipulating it would be the same as if manipulation a normal double edged balisong, except if you screw up it is a lot worse

I sincerely doubt that one will ever be made, but that would be really sweet to see.
Edit: Let me make something a little more clear: I do not like combo edges, but I do like fully serrated blades, if a 47 or a 43 (or any balisong) came out with a fully serrated blade I would get it. For beautiful looks or pretty lines plain edge is best, but for interesting looks and "Wow! That is the strangest blade I have ever seen!!" fully serrated is the way to go.
