The missile defense plan has several components and the announcement only covers one on them - the ground based interceptors.

SBIRS High and Low are years away from their first flight. SBIRS Low in particular is having problems.

The Airborne Laser has only began making test flights. It hasn't fired the laser in flight yet and is a long way from being operational (if it is successful).

The Navy has had some success shooting down shorter ranged missiles using Aegis cruisers, but that's only in the early test phase. I only know of 2 or 3 test flights in the program to date.

Other programs for shorter range missiles like the THAAD and Patriot PAC III have had their share of problems as well.

There still needs to be quite a few upgrades to existing radars like BMEWS and PAVE PAWS. There also needs to be new radars like the X-Band system deployed. The radar upgrades and new systems are integral to the target discrimination phase of the mission.

This announcement is basically a limited deployment while testing continues. Without the other components like SBIRS and the X-Band radar, the system will have very limited capability. Still, it's a start. They were planning on putting an X-Band radar on Shemya but the last I heard, that may not happen. Perhaps they'll build one closer to Fort Greeley.