- Energy: To my understanding, the computing power we use for mining our coins is all wasted. The only reason for the power requirements is to force scarcity and distribution. We need to find a greater purpose for the computing power, something that makes outsiders want to join the community because it is doing some good in the world. We need to include something like folding@home or analyzing DNA or something to benefit society.
the road to establishing a currency AS an actual currency for buying things instead of just another financial commodity is always going to be a long and usually difficult road. Making the currency do social work is a nice thought, but it's not the point. It's a CURRENCY. You take the currency and use it to PAY people to analyze DNA or whatever to benefit society. I'm not opposed to coins that might do something like that, such as devcoin, but it might(not WOULD) prevent it from becoming a general use currency.
- VALUE: Cryptocurrencies are currently linked very strongly to the USD/EU. Many miners simply mine the currency in order to sell it for USD. If these are ever going to have a chance at surviving, the infrastructure needs improvement. That is happening to a point, but really what we want is not 'x coins buys x dollars' but rather 'x coins buys a soda' as a way of thinking. What if the coins, as they gained value against other currencies, actually multiplied by 10's? so if its initial worth was $0.10 US, 10 coins buys a soda. If the value against the USD goes up to $1.00 per coin, everyone coins get multiplied by 10 (sort of like splitting a stock). The purpose would be to keep the purchasing power of a single coin approximately constant so that resellers can set prices in terms of our currency and not risk their prices being way off due to massive market swings like bitcoin has experienced.
The problem with this is that it will only stabilize the currency in relation to whatever currency you're pegging it against. Various currencies go up and down relative to one another all the time. That's why there's a huge multinational market of speculation in currencies. So, basically, you're sort of making it a sub currency of whatever nation issues the other currency that you're pegging to.