On the surface, your repository config looks right, but there could be something subtle that's hard to see in how it is formatted in the forum.
I'm using the following repositories in the Spring Social showcase and just confirmed that they do download M2 artifacts.
Code:
<repository>
<id>org.springframework.maven.release</id>
<name>Spring Maven Release Repository</name>
<url>http://maven.springframework.org/release</url>
<releases><enabled>true</enabled></releases>
<snapshots><enabled>false</enabled></snapshots>
</repository>
<!-- For testing against latest Spring snapshots -->
<repository>
<id>org.springframework.maven.snapshot</id>
<name>Spring Maven Snapshot Repository</name>
<url>http://maven.springframework.org/snapshot</url>
<releases><enabled>false</enabled></releases>
<snapshots><enabled>true</enabled></snapshots>
</repository>
<!-- For developing against latest Spring milestones -->
<repository>
<id>org.springframework.maven.milestone</id>
<name>Spring Maven Milestone Repository</name>
<url>http://maven.springframework.org/milestone</url>
<snapshots><enabled>false</enabled></snapshots>
</repository>
Craig Walls
Spring Social Project Lead