The current deeplearning feature in Graphlab Create supports building classifiers using convolutional network and fully connected network. It does not quite have the support for building a neuralnet language model.
If you want to implement using Google's word2vec, please take a look at the SDK page: https://github.com/graphlab-code/GraphLab-Create-SDK
It will help you to using the existing word2vec implementation and make it work with GraphLab Create in python. This could be a very interesting project, and please let me know if you are excited about doing it. I will be happy to offer my support.