Can you get statistical data on research paper submissions and publications? For a class project in machine learning, I am considering building a set of predictors where the feature set includes information about the topic, keywords in the title, the authors, the date, etc., and the outputs are probability of getting published, expected citation impact, etc.  

I would like to choose a single journal such as Nature for example.  Will it be possible to collect the necessary data to accomplish this? Anyone have tips on where I can find statistical data about particular research journals?
IMHO, this is unlikely to fly. Some journals might give you statistics on the number of submitted and accepted publications. But submission to a journal is typically confidential and as an author, I would be pretty upset if Nature revealed this information to someone else.

Where you might be able to do similar analysis is a site like arXiv.org. It's used heavily in physics in other fields as a preprint service, and there are usually notes where and when a submission is accepted to a journal. Keywords are also included. The difference is that not everyone submitting to Phys Rev necessarily uses arXiv.org.