Meryl Streep has appeared in the following films since her role in the film 'Music of the Heart' in 1999:

Artificial Intelligence in 2001, she provided the voice for Blue Mecha.
Adaptation in 2002 in which she plays Susan Orlean.
The Hours in 2002 in which she plays Clarissa Vaughan.
Angels in America was a 2003 miniseries.
The Manchurian Candidate in 2004 in which she plays the part of Elenor Shaw
Lemory Snicket's A series of Unfortunate Events in 2004 in which she plays Aunt Josephine.
Prime in 2005 in which she plays the part of Lisa Metzger.
A Prairie Home Companion in 2005 in which she plays Yolanda Johnson.
The Ant Bully in 2006 in which she provides the voice for the Queen Ant.

Other films that are not yet released and are in various stages of production are:

Dark Matter (2007)
Evening (2007)
First Man (2007)
Wanted (2007)
Dirty Tricks (2008) and
Chaos (2007)