Odd that this hasn't been said yet?

Microsoft Parallel Data Warehouse includes Hadoop to help with management of unrelated data.

The Microsoft Analytics Platform System is your turnkey big data analytics appliance combining a high performance MPP SQL Server data warehouse with Hadoop into a single solution that offers seamless integration for of all of your data.

Apache Hadoop to Windows - http://hortonworks.com/partner/microsoft/[/url]

That being said, I don't know how common it's being used, but it is apart of their Microsoft Data Warehouse Appliance. It's also free to download last I checked directly from Hortonworks.

For me, Kimball's book has been great and I would highly recommend it.