The Battle For Time (HaChodesh)
Several explanations have been provided as to why the first mitzva given to Bnei Yisrael is blessing the new month. One suggestion is that now that as a nation we were "free," it does not mean that we are to waste time. The first thing we need to do is to sanctify time in order to ensure that we are productive and that we perform mitzvot as avdei Hashem and not as avadim leParo. See Sforno (Shemot 12:2): Now that time is in our hands, we have to use it productively. (- "Shalom Rav" sefer footnote on pg343) Rav Rosner mentions this idea in his "Vacation in Judaism" Sichas Chaim (skip to 03:27).