Hi Eric, I know this post is a few years old but here's what worked for me:
Create an email script token in Active Marketo Tokens. I called it "Current Year"
Open the email script editor ("Click to edit") and enter the following:
That should dynamically populate the current year using Velocity
Don't forget the timezone though:
Only matters for one day out of the year, but that may be the day somebody decides to QA it...