Yes I did see the export command but to automate this that may be more of a problem, I guess it depends how much control you have over the mongo db and if you can setup jobs on the Mongo side.

Here is another link from the mongo site for the C# driver:

http://docs.mongodb.org/ecosystem/drivers/csharp/

I have not reviewed the code but worth downloading... you could build a dll that can then be referenced in a Script Component in SSIS setup as a Data Source.