All,
I'm just getting started with hsXenCtrl [1] as both a fun way to play
with Xen and become proficient with Haskell FFI.  Once I get my
community.haskell.org account squared away I'll likely setup a public
darcs repo (and a homepage somewhere).

As for modules: I intend to expand on the trival FFI bindings in
System.Xen.CBindings and there'll be a higher level interface in
System.Xen (functions will standardize on returning Either or throwing
exceptions, hiding the xc_handle open/close, etc).

Typical Disclaimers:
The _only_ thing I've actually done with this, just tonight, is pause /
unpause domains.  API is subject to change!  Only my exact build of Xen
is sure to work, and no promise even then.

TomMD

[1] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hsXenCtrl