One misnister did attend, and Kerry travelling to PAris end of the week.
As said above, the important part is faceless 1.5 million people in Paris and about 3.5 millions in France (including saturday's rallies)
What i saw was exchange of flowers between muslims and jews, making common selfies etc. May not last long, but i think it has been a strong signal.
This "unité nationale" will last 1-2 weeks,and we will live like if this never happened and there will be the same problems. (I hope to see that i'm wrong though)