I have done very little economics, but to me being 'backed' suggests the bitcoin should be redeemable for the powered used to generate it, which is not the case. For a potential bitcoin purchaser, the only value is the future ability to spend it, like a fiat currency.
So my question is: Are the claims that bitcoin is backed meaningful? Specifically does the work required in creating the coins change the economics of the coin in any way other than controlling the rate of currency 'printing'?
[1] http://bitminer.info/ [2] http://forum.bitcoin.org/index.php?topic=57.0