first step is create a public testnet with many automatic fake transactions. this is very simple. you have now the funds with the bitcoin foundation.
I still think that sitting around all day doing pretend transactions, even if doing it on salary, isn't very motivating. Though maybe with a huge enough salary it could be rendered somewhat tolerable.
That is why I have always leaned more toward the approach of doing it with real "play money" - "real" play money - game money.
The big problem with the testnet for that is the restarts. Players don't like to know all their hard-earned game-money is going to vanish poof gone any time the developers decide to do a restart.
Get a bunch of players using a bitcoin clone for their game currency though and maybe you could build up a large motivated bunch of people who will happily do all kinds of imaginary commerce, lots of transactions, maybe even try to do doublespends against enemy nations' transactions, maybe try for 51% hash power to block enemy nations' blocks completely, all kind of fun stuff.
For example we could apply the merged mining patches to bitcoin 0.8, add a -playnet flag to commandline and config file that activates the merged mining as a secondary chain capability so we could even do it in merged mining mode as a secondary chain, have that flag also change cosmetics such as the name of the coin and its logo and favicon and such, its data directory, its config file. Presto, a playnet alongside the testnet, a playnet that lets players derive motivation from the idea their playcoins are not intended by design to be ripped out from under them at any moment like happens on testnet.
The code needs all those cosmetics such as the name of the coin, its datadir, its IRC channel, its handshake, its ports and so on to all migrate to one easy to find place anyway so the ever growing number of altcoins don't each have to waste time getting directly to the nitty gritty details that make the code run as this that or the other Crunchy Berry Coin of the Day.
Basically the easier it is for altcoins to use the latest bitcoin code, the better such altcoins will be able to serve as testnets, playnets, cornercasenets, edgecasenets and so on and so on; new features can be deployed first in some playcoin or other - a real playcoin, not a vanish gone up in smoke coin like testnet coins are - for some heavy real-play workouts and shakedowns and burn-ins before deployment to the Serious Real Money bitcoin chain.
This is the same stategy I am using for Open Transactions testing and development: use it first for some real game trade and commerce and finance, for real, to see that it all works and load-test it and so on.
-MarkM-