Yes, I am applying. The way it worked last year was that I submitted my application via ResearchNet, the Graduate Chair nominated me, and then it went through an internal departmental project. After that, it went to the Faculty of Graduate Studies and Research at the University and then they nominated for the national or rejected (I was rejected for this one, made it to the national competition for the Trudeau and then wait listed for the SSHRC). This year, I am focusing on the Vanier and SSHRC. While I loved the process of the Trudeau, it isn't for me (I have a child and can't do the amount of travel it requires.)
I had multiple people go through my application but sometimes its just the committee too and what is "hot" as a research topic that year. But I have had a friend who won the Vanier helped me and offered to help me again. Also, check out ANY and ALL workshops that the faculty of graduate studies holds. I didn't last year and I think I suffered for it. This year, I am going to both the writing workshop and they have a Vanier writing bootcamp that I am going to attend. I have been told that these can be crucial to learning how to frame your topic for a vast audience.
Good Luck!