My friend tried to launch snapshot 12w22a via the Minecraft Dev Launcher version 0.9. The game just... wouldn't start. Heres the developer console log:

Trying to log in...
Logged in successfully
Getting syncinfo for selected version
Queueing library & version downloads
Download job 'Version & Libraries' started (8 threads, 1 files)
Finished downloading C:\Users\James Wultsch\AppData\Roaming\.minecraft\versions\13w22a\13w22a.jar for job 'Version & Libraries': Used own copy as it matched etag
Job 'Version & Libraries' finished successfully
Launching game
Unpacking natives to C:\Users\James Wultsch\AppData\Roaming\.minecraft\versions\13w22a\13w22a-natives-14375324800596
Launching in C:\Users\James Wultsch\AppData\Roaming\.minecraft
Running: C:\Program Files\Java\jre7\bin\javaw.exe -Xmx1G -Djava.library.path="C:\Users\James Wultsch\AppData\Roaming\.minecraft\versions\13w22a\13w22a-natives-14375324800596" -cp "C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.4\jopt-simple-4.4.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\com\paulscode\codecjorbis\20101023\codecjorbis-20101023.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\com\paulscode\codecwav\20101023\codecwav-20101023.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\com\paulscode\libraryjavasound\20101123\libraryjavasound-20101123.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\com\paulscode\librarylwjglopenal\20100824\librarylwjglopenal-20100824.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\com\paulscode\soundsystem\20120107\soundsystem-20120107.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\argo\argo\2.25_fixed\argo-2.25_fixed.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\org\bouncycastle\bcprov-jdk15on\1.47\bcprov-jdk15on-1.47.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\com\google\guava\guava\14.0\guava-14.0.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\org\apache\commons\commons-lang3\3.1\commons-lang3-3.1.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\commons-io\commons-io\2.4\commons-io-2.4.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\libraries\com\google\code\gson\gson\2.2.2\gson-2.2.2.jar;C:\Users\James Wultsch\AppData\Roaming\.minecraft\versions\13w22a\13w22a.jar" net.minecraft.client.main.Main --username 1Sara2Kate3 --session 3567576076706427098 --workDir "C:\Users\James Wultsch\AppData\Roaming\.minecraft"
---- YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----
---- YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----
---- YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----
---- (We'll do this automatically later ;D) ----
Client> Error: Could not find or load main class Wultsch\AppData\Roaming\.minecraft\versions\13w22a\13w22a-natives-14375324800596
Game ended with bad state (exit code 1)
Deleting C:\Users\James Wultsch\AppData\Roaming\.minecraft\versions\13w22a\13w22a-natives-14375324800596