how much text data is required for a meaningful use of word2vec how much data does word2vec require?  Are there any public data sets that are useful?

For example, could it be that 1000 newspaper articles are enough to use word2vec?  

Here is a word2vec tutorial from Kaggle that uses 50,000 movie reviews.  I am trying to understand the scale of the word2vec input.
As word2vec is a neural network, it benefits from very large datasets.  The Kaggle dataset is 50,000 reviews * ~5 sentences per review, so about a quarter million sentences.  As they note, they get approximately the same results using bag of words and word2vec.  One thing which is of note, since the review data comes from the internet, the sentences are much more loosely structured than what you would encounter in a corpus of newspapers, which typically go through grammatical review.  A great dataset for training word2vec on structured language is the wikipedia dataset:
https://en.wikipedia.org/wiki/Wikipedia:Database_download