Trying to understand presentation compiler and build manager

Hi,

I'm an Emacs user intrigued by the new IDE support code in
scala.tools.nsc.interactive. I'm wondering if I might be able to expose
the CompilerControl interface to Emacs with a SLIME+Swank-like protocol..

Ideally I'd like to have a stand alone process dedicated to a scala
project. The process would continuously monitor source changes and do
any necessary recompilation ( I assume this is what BuildManager is
intended for). It would also expose a high-level interface for querying
for type information, method completions etc. This seems to be what the
presentation compiler (with CompilerControl interface) is suited for.

So my question is what's the best way to use these tools to maintain an
up to date, incrementally compiled state, and then how would one go
about making efficient queries against that state?

Thanks!
Aemon