I have not, and the other folks I've talked to haven't received anything either.
The link on the bottom of the main USMMA page has changed from "Class of 2014 logging in book" to "Class of 2015 logging in book" but the link just says "coming soon" so I think the logging in book will be coming in the mail next.
In the mean time start working on your TWIC.
Also, as an additional reference to get you going on what things will be like, you can view the class of 2013 logging in book.