As Sazerac states, next Fall is when the first batch of borrowers will be eligible for forgiveness.
Hopefully by then we'll know of Congress plans to repeal/adjust/leave alone PSLF. Maybe they "grandfather" people in, maybe they don't.
I also imagine the forgiveness process would take quite a while, given that it's the government. It's important to note you have to keep working at a PELF-eligible job and make monthly payments until you actually get forgiveness, so it's likely to take a little over 10 years (and thus maybe the first group doesn't get anything forgiven until closer to the first half of 2018)