I think these hires are for an expected ramp up of near term and future development, I doubt they need these guys for the Q1 Milestones, I think it's more likely that they're anticipating a ramp up of developments(ie: Q2 Milestones, or more Fab Integrations, helping our clients/partners?).
I'd assume they have the staff required to make the 40nm PDK, VCSEL & R-O. I surely hope so anyways..
My take is that they are planning on being busy in 2015.