Speaking of the best books of 2009, I’d list John Sailhamer’s The Meaning of the Pentateuch (IVP Academic, 2009). This from page 504:

“[Matthias] Millard argues that the Psalter, as such, originated in the Persian period. It was conceived as a collection of prayers for the Diaspora and functioned as a replacement for temple worship. In reading the Psalter, one was both oriented to the temple and, at the same time, absolved from actually having to worship there. The Psalter thus was intended to promote the importance of the temple pilgrimage while at the same time being a substitution for the temple itself. It was a private surrogate for the pilgrimage to the postexilic temple in Jerusalem.”

Sailhamer next focuses on the three strategic psalms: 2, 72, and 145. A nice little bonus in a book on the Pentateuch!