I got to thinking... often times Altera includes preview or beta releases of new tools with Quartus releases. I just searched my install folder and there is indeed a preview of Qsys in the 10.0sp1 release!
./10.0sp1/quartus/sopc_builder/bin/qsys-edit-preview.exe
From a Nios II Command Shell you can just type "qsys-edit-preview" to load it.
I wonder if this preview is a good representation of how it will really look. I was a little surprised to see how similar the preview looks to the existing SOPC builder.
dvb,
You mentioned future versions will give more control of the switching fabric. Does this includes more flexible arbitration methods? The simple arbitration share settings that exist now are not very flexible. I have seen and just started to look at the MPFE (multi port front end) that is part of some of the Altera video reference designs, but I think it would be great to have this functionality directly part of SOPC or Qsys.