Late to the party but just picking up a used JTV-59 this week. It took me a while to finally get my hands on one that I could play long enough to decide the neck really does feel good in my hands and the mag pickups sound good to my ears, so even if the electronics lose their function the guitar will still get played. Similar to my VG Stratocaster, it is still an American Standard Stratocaster with all that sound and playability even if the electronics die. The JTV-59 will give me more of electronic fun stuff to play with, and I like it has an ON/OFF switch.
With the way electronics shrink, and considering it is a decade since these were designed, I would think building the next gen as a swappable board could be relatively easy. If someone at Line 6 wants that to happen... If the desire is to make the routed area as compact as possible for the next gen, then we maybe out of luck.