Let me put it this way.  I was a DBA on both for close to 6 years in a large investment company, and I can tell you this.  I was able to manage about 15 SQL Server databases but only 4 Oracle, and the Oracle ones took 75% of my time.

I would only put warehouses on Oracle.  SQL has to prove they can do what Oracle's been doing for years.  The direction MS is going with partitioning, etc, is the right one, but they have to prove they can function on a 64 bit platform before I'd consider putting a TB warehouse on SQL Server.