In my last company our "futurology" was limited to perhaps a 1 or 2-year timeframe. We designed our system using some key components that we believed would be available in quantity at an acceptable price -- not now, but when we needed them for volume production. We tracked and often worked with vendors in that space (example: 10 Gbit/s lasers and detectors for single-mode fiber). We used expensive prototypes during development when necessary, but when it was time for customer shipments the initial component price/availability targets had been hit, or were at least within sight. This technology required no scientific breakthroughs, just hard work, and the evolving communications network meant that there would be a strong demand for these components.
This approach has risks but potential big payoffs when you can leapfrog your competition by a full generation, and this is exactly what our Venture funders were looking for. We ended up redefining our market segment and got the big payoff.