Up to now, its not possible to use maven repositories. I'm using ivy as dependency management tool, but also use maven2' s ibiblio repositories. And this is working for ivy:
<dependency org="oracle" name="ojdbc14" rev="10.2.0.2" conf="*->default"/>
Maven2' s dependency could be something like that:
<dependency>
<groupId>oracle</groupId>
<artifactId>ojdbc14</artifactId>
<version>10.2.0.2</version>
</dependency>
Notice that i define http://download.java.net/maven/2/ and http://mirrors.ibiblio.org/pub/mirrors/maven/mule/dependencies/maven2/[organisation]/[module]/[revision]/[artifact]-[revision].[ext] as external maven2 repos on my ivy settings.