I have said it before, but asymptotically limiting the number of bitcoins has bad repercussions.
One of the most serious problems is hoarding. Whenever you have a commodity that has a fixed supply against an increasing demand, inevitably hoarding occurs.
This is one of the key reasons why currencies are designed to expand: steady expansion of a currency improves liquidity.
Bitcoiners complain about non-use of coins and liquidity, but I think it is largely their own fault for capping the bitcoin supply, an elementary design blunder. Not only that, the closer we get to 21 million and the more users there are, the more intense the hoarding will become. This is basic economics stuff. Seriously, people around here need to read Adam Smith. (Hey, I know its a fat book, maybe your mom can help you with the big words.)
Also, as long as I am ranting, the procedure of giving bitcoins to people who run computational server farms is totally off the wall. The natural way to do P2P currency expansion is to award new coins proportionately to those who hold existing coins. Duh.
Put your time where your mouth is and support my idea for EnCoin. It requires pretty much a completely new codebase, so it is a bit far yet from being a reality.
If too many people hoard and the prices rise, more people can create new coins (and there are rules governing creation that make it much less profitable for server farms and such).
Merchant reputation provides security for the network and merchants are encouraged to gain this reputation in the form of refunding some of a mandatory transaction fee. Any unrefunded fees go to those who already hold coins.
No big payoff for being an early adopter though since it is attempting to be a currency rather than a commodity. :/