If most coins work in the same general way (in regards to the client -- I'm not familiar with programming too much) could you implement a sort of module-type system, such that someone can just add a file in, like "doge.coin" that would hold the parameters needed to parse DOGE's database? Not sure if I'm explaining this well enough but basically a way to quickly allow everyone to add their own coins to the client.
It is possible.
You can edit file coin-chains.xml to add your own currency if it uses one of supported algorithms: SHA256, SCrypt...
But each real crypto-currency has some differences which can be expressed in C++ only.
