I'm sure the same was said back when 40, 64, 128, and 256 bit encryption was coming out. SHA512 is part of SHA2, I remember when everyone was talking about how insecure SHA1 was with that significant *flaw* and how we all need to move to SHA2 because it was well defined, well supported, and well analyzed; sound familiar?
I'm not aware of any 40 bit hash length. The reason for SHA512 and Whirlpool's excessive bit lengths are just for such future proofing. A collision has a 50% chance of occurring at half of the bit length (roughly), so weak hashes such as MD5 would have problems at around 2^64 elements, this was well known and few people thought this was impossible to achieve in the future.
So no, it's not exactly familiar. Wanting to double it again because the idea is to form a basis for a new economy is not crazy talk - there is no technical reason not to use Whirlpool or SHA512 (or both). The only hurt would be a lower hash generation rate... which isn't exactly a problem.
I'm not betting anything for the simple fact that unless you can see into the future, we work with what we have in front of us. We can debate all day that in the future computers will be a million times faster or that some math genius is going to discover a flaw in the system that would bring everything down. I'm well aware of many peer reviewed papers and tech journals, even blogs about encryption. Not everything in existence, as I don't have the time for all of it, but enough practical experience to be able to visualize what it would really take to do what you propose.
Your participation is your bet.
10 years is a good a guess as my 1 million years. SHA1 still has not been broken, but you can brute force/exploit flaws on a super-computer in under 60 hours if you have $35 million to throw at it.
$35 million to swipe any single person's bank account.
I'm not trying to nitpick your post, just offering up my opinion and I certainly respect yours. I think we can both agree that if the encryption is bumped up another notch in the future, it would be a good thing for the system and community as a whole.
I'm honestly rather keen on exploring alternative possibilities for generation. As one Slashdotter put it, the current scheme is like claiming a forest of unknown size as currency, burning it down, then proclaiming the most select 21 tons of ash as the representative medium. I have an idea but I have no clue about who would be interested.