That's the million BTC question now, isn't it? Too many variables to consider but yes, they are undervalued currently (imo).
Not sure if it's a million BTC, since the projected BTC revenue from mining is just above 120K per year, but yeah, it's a pretty important question :-)
I've said this before, and please excuse any excitement in my voice, that AM has an extremely bright future due to the fact that they are diversified already and can diversify further. BFL can't suddenly change and say "You know, we want to start mining with all the equipment we haven't sent out to clients, KTHXBYE". Avalon could perhaps do so, but again, struggling with getting their act together.
AM, on the other hand, has already done both mining and equipment sales, and have a ton of other options too. One of the business areas is a fixed reward game, which is a problem if that were the only business area, but like BFL and Avalon, AM can easily shift focus to more equipment sales, which is a non-fixed reward game, or any number of other related ventures, fixed or not.
In other words, I can't really see that even with upcoming farms like 100TH, vendors like BFL/Avalon, that any of them can compete with AM simply due to the flexibility of AMs operation.
.b
