I liked markm's post on market backing.
I consider this extremely important.
Consider for example if when 10% of all the coins a chain will ever contain have all been sold for $0.10 each all that wealth used to buy them had been put back onto the buy-side, it would have been enough backing to back all the coins ever to exist all at $0.01 each.
So basically as coins sell for more and more each, the floor backing could constantly grow.
If when bitcoins had been selling for $1000 10% of all bitcoins ever to exist had been bought for that much, from someone or someones willing to actually "back" the currency, that would have been enough dollars in the system to "back" every bitcoin ever to exist at $100 each, basically gaurantee-ing a floor price of $100 from then on.
With coins such as DeVCoin, which continue to mint coins forever, providing such cast-iron floor price by means of deep solid buy-side order-books is harder. But maybe worth attempting regardless.
Basically I consider the ability to reliably "back" a currency to be one of the very few "advantages" of a centrally-issued currency. The issuer gets all the wealth used to initially purchase the currency thus is in a position to "back" the currency.
Everyone with long-term interest in a currency should probably consider trying to "back" it to whatever extent they can afford...
-MarkM-