Personally I think it's an awesome idea that reduces the effects of spam, essentially a self cleansing p2p network, while also giving funds back to the network in a fair manner.
Im going to go against the grain here and say its a good idea with the following conditions:
* no/minimal transaction fees.
* you are able to bounce coins back and forth between two addresses with 0 charge.
Then if I were to get into these coins, id simply setup a perl script to bounce my coins back and forth.
When I cease using the coins (ie dead) my PC will eventually be turned off (if not claimed by people in my will) then they are slowly reclaimed by the miners which I see as paying for infrastructure.
On the flip side, I also feel its simply not required if you can split the coin to ever smaller bits. As more is lost, value rises and people buy the same stuff but with smaller amounts of coin.
If you wanted to get more support behind the idea, perhaps set the reclaim time to a very large increment, perhaps 1 month or 1 year ?
At those figures Im sure people simply wouldnt care and would be more inclined to believe it is there for the networks benefit.