What if bitcoins had expiration dates?

What would happen if every newly minted bitcoin had an expiration date, after which it would be rejected by the system?

Lets say the total number of bitcoins in circulation remains true to the current chart, but the difference is that eventually old coins are being destroyed at the same rate as new coins are being created.

This would shift the entire system from being highly deflationary into some other category. Old coins which have had their keys lost would eventually be recycled.

The issue of early adopters getting extremely rich would be diminished somewhat. They'd still get rich but the price would have to increase fast enough, not simply rise in price over a very long period of time. Older coins wouldn't be worth quite as much as newer coins.

The block chain would not forever increase in size, because every coin has a definite beginning and a definite end. Old addresses with dust in them would have a limited lifespan.

The reduction in value as coins age would ensure a minimum level of money velocity, and transaction fees and other factors would set the maximum money velocity.

It would more closely mirror wheat receipts in ancient egypt as opposed to mirroring gold as it does now.

There are a lot of interesting possibilities here.