I have looked into this, and from what I can tell, the actual scala source doesn't come with sbaz ( it comes with sbaz docs though ).
Anyways, for this to work, you need to also make sbaz separately afaict.
Sbaz website: http://www.lexspoon.org/sbaz/
Sbaz source (latest): http://www.lexspoon.org/sbaz/downloads/sbaz-1.25.tar.gz

Now we need to make a decision if sbaz should be in it's own separate package, or should it be built along with scala.
P.S. I'm still talking to upstream and trying to get a more definite answer.

Edit: Forgot to mention that another option would be to just use their distributions which are already compiled (into a virtual machine language).

I posted a thread about this "problem". Waiting for responses. Link: http://www.scala-lang.org/node/5163

I have also posted another thread on another forum about this issue. Waiting for responses. Link: http://scala-forum.org/read.php?22,1015

Note that using sbaz is a package maintenance system and would result in files changed and installed outside of pacman's control. It would most likely require a central scala installation (i.e. everything under one directory) like the scala installers make, so including it would probably necessitate changing the package to install like that (i.e. in /opt/scala). Maybe the better approach would be to make arch packages for the packages that sbaz makes available?

As far as I can tell, you can package it separately: http://gentoo-portage.com/dev-java/sbaz

any decisions?

upstream scala source doesn't come with sbaz, which is why I think sbaz should be a separate package

code found at:
http://www.lexspoon.org/sbaz/