I believe these additional points will help the newer user avoid build frustration.

0) The multi-jvm build environment currently only supports Scala (full) build configs, not build.sbt.
(As a personal note, though, I have a build.sbt that almost works).
1) The correct command to execute multi-jvm tests only is: multi-jvm:execute-tests
2) By default, the test task in sbt only runs regular, not multi-jvm, tests. If you want to have the test task (as well as multi-jvm:test) run both regular and multi-jvm tests, you need this block in your Build.scala:
executeTests in Test <<= ((executeTests in Test),
(executeTests in MultiJvm)) map {
case ((_, testResults), (_, multiJvmResults)) =>
val results = testResults ++ multiJvmResults
(Tests.overall(results.values), results)
}

(A comment should also be added to the code example in multi-jvm-tests docs, that this block makes the test task execute both regular and multi-jvm tests).

3) The default directory for multi-jvm test source is src/multi-jvm/{scala, java}, which can be overridden.... like this:

unmanagedSourceDirectories in MultiJvm <<= Seq(baseDirectory(_ / "multi_node_test")).join

This setting needs to come AFTER the multi-JVM settings are added, or else it will be overridden by the multi-jvm defaults.

4) The following block of code in the multi-jvm build file contains references outside the example, maybe it should be taken out:

dependencies = Seq(remote, actorTests % "test->test",
testkit % "test->test"),

It is only relevant specifically for the Akka project build as it references other Akka sub-projects.

I can attach an example of my Build.scala, which I believe is much more helpful than the current example as it is taken from an independent project outside Akka.

Points 1 and 3 are I believe the biggest stumbling blocks to new users to multi-jvm getting it up and running.