This is a great question. I've actually contemplated this very same thought on more than one occasion. My first time 'round was back in the mid 90's when most of the classic were already well beyond their 10th birthday.
Anyhow, I have an opinion on the subject, both as a collector of these games and a manufacturer of reproduction parts as well.
Being a collector, maybe not as "hardcore" as some, I still have an incredible home arcade filled with so many games it would make your head spin. What matters to me the most is that each of these are dedicated machines that will faithfully run the game for which it was designed....oh, and they have to LOOK and FUNCTION perfectly!! Sure, I think MAME is really cool and totally has a place -- particularly for people who may not have as much space as I do or the will power to maintain 100+ games. LOL But the point is that because I (and many others) are thrilled to own these machines, there will be drive to maintain them no matter what. Of course, this all hinges on the idea that people will still want to collect these down the road. My thought on that: people collect anything they can get their hands on! Always been that way, probably always will be that way.
On the flip side, as a manufacturer of reproduction parts (which stems from the fact that I'm a collector), I am able to look at any part of a game (controls, cabinet, circuit board) and make a faithful "copy" of said item. There are a bunch of people out there dedicated to reproducing the parts to keep these machines running. Old circuit boards are not really a concern... yet. Most are easily repaired, probably even 30 or 40 years down the road from now. Heck, maybe even longer. The trouble spot will be in obtaining the correct components necessary to repair or reproduce the boards, but that may not be a real issue for quite some time. So far, there are only a very few components which are completely MIA now that were plentiful back in the 80's. That said, some ingenious people out there have figured out ways around this real problem.
I think these games will be collected, restored, maintained and operated (even if only in our homes) for at least another 3 or 4 generations. By that time, our plasma power systems will be incompatible with 120V arcade games. LOL
I really do enjoy this topic, btw.
David Adams
RAM Controls