I created a project using:

mvn archetype:generate \
 -DarchetypeGroupId=net.liftweb \
 -DarchetypeArtifactId=lift-archetype-sbt_2.8.1 \
 -DarchetypeVersion=2.3 \
 -DarchetypeRepository=http://scala-tools.org/repo-releases \
 -DremoteRepositories=http://scala-tools.org/repo-releases \
<snip>

but the created project actually uses scala 2.7.7

 > cat project/build.properties
#Project properties
project.organization=Lift
project.name=Lift SBT Tempalte
sbt.version=0.7.4
project.version=0.1
def.scala.version=2.7.7
build.scala.versions=2.7.7
project.initialize=false