I don't care if you dislike Second Life, think it is stupid, or whatever, the fact that they will open source their client is a bold and smart move. This means people can and will be able to create the system they want and make the kind of software they want it to be. Developers will be able to do infinitely more than they could before now that the Second Life client will be their to tinker with. If you want to breathe fire into your software, give it away and let the developer community loose on it. Second Life's creators think this move on their part will help the community grow faster than ever before. The main idea behind Second Life is a user-generated world, and now this paradigm extends to the client itself.