Does Ijmaa' play a role in Islamic society today?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

There is no doubt that the consensus of the scholars whether in the earlier times or in this contemporary era, about matters on which there is no text in the Quran  or the Sunnah, is of great importance and plays an important role in the society. That is because the consensus of the scholars is an absolute evidence that a Muslim is bound to abide by the view of all the Muslim scholars. So if there is a consensus of the Muslim nation that a given matter is forbidden or permissible, then this consensus applies to all Muslims and it is not permissible to act contrary to it.

Ibn Mas'ood said: 'Whatever the Muslims (collectively) view as being good is in the Sight of Allaah good, and whatever the Muslims (collectively) view as bad and evil is in the Sight of Allaah bad and evil.' [Ahmad and Al-Haakim] 

Allaah Knows best.