Note: Don't miss a thing! Join the Ethereum London skype channel - add 'stephan.tual' to your contacts and specify 'London' in your request.
Ethereum is a platform and programming language that makes it possible for any developer to build and publish next-generation decentralized applications. In short: Ethereum is the web, without the web servers.
Ethereum can be used to codify, decentralize, secure and trade just about anything: voting, domain names, financial exchanges, crowdfunding, company governance, contracts and agreements of most kind, intellectual property, and even smart property thanks to hardware integration.