Each VLS tube has 4 missiles, giving the ship 32 ESSMs. That number is still nowhere close to that carried by US/Japanese/S.Korean AEGIS vessels, but it is quite formidable for a frigate. It may not be good enough for the South Koreans or the Japanese or the USN, but for Norway it should more or less fit the bill quite well.
On a different note: I am still wondering why the AEGIS system is still a PESA and not an AESA?