If you're going to build serverless thing to take advantage of market hype why not at least try and build one that has data locality like ZeroVM/ZeroCloud (http://www.zerovm.org/zerocloud.html) and Manta (https://www.joyent.com/manta)?
It isn't exactly a simple thing. I looked at it and got some stuff working in it a while ago, and it certainly limits what you can do.