This first article explains the purpose of the document:

In this decree the Council seeks to describe the nature, character, and diversity of the lay apostolate, to state its basic principles, and to give pastoral directives for its more effective exercise. All these should be regarded as norms when the canon law, as it pertains to the lay apostolate, is revised.

Recently Pope Benedict
called for the laity have more responsibility in the Church

But at the October 2012 Synod on Evangelization (see comments)
not one lay person will be on the list of decision makers
(please correct me if I'm wrong)

c.f. The Laity, a good idea at the time? by David Timbs

In other words, the teaching of the beautiful document on the laity
has been vetoed/ignored/deleted/opposed by Pope Benedict

So, what can ordinary folk like ourselves do when Vatican II says one thing and a pope says another?

Pray for a Vatican II pope !