Why would it? Why on earth would it???

Look, Jakob Nielsen reports his bandwidth in 2014 is 120Mbps, which is around the 90Mbps figure Gavin mentions for his own calculations. Let's use 100Mbps as a "good" bandwidth starting point which yields:

1: 100
2: 150
3: 225
4: 338
5: 506
6: 759
7: 1139
8: 1709
9: 2563
10: 3844
11: 5767
12: 8650
13: 12975
14: 19462
15: 29193
16: 43789
17: 65684
18: 98526
19: 147789
20: 221684

Researchers at Bell Labs just set a record for data transmission over copper lines of 10Gbps. So we can use that as a bound for currently existing infrastructure in the U.S. We wouldn't hit that until year 12 above, and that's copper.

Did you not read my earlier post on society's bandwidth bottleneck, the last mile? I talk about society moving to fiber to the premises (FTTP) to upgrade bandwidth. Countries like Japan and South Korea already have installed this at over 60% penetration. The U.S. is at 7.7% and I personally saw fiber lines being installed to a city block a week ago. Researchers at Bell Labs have achieved over 100 petabits per second internet data transmission over fiber-optic lines. Do you realize how much peta is? 1 petabit = 10^15bits = 1 000 000 000 000 000 bits = 1000 terabits

That's a real world bound for fiber, and that's what we're working toward. Your fears appear completely unsubstantiated. On what possible basis, given what I've just illustrated, would you expect bandwidth to stop growing, even exponentially from now, after only 10 years?!?