SharePoint 2010 as an application storage can be used SAN, NAS or DAS (SCSI or SATA or any other technology).

Please refer to the below articles for more information:

Storage and SQL Server capacity planning and configuration (SharePoint Server 2010)

http://technet.microsoft.com/en-us/library/cc298801.aspx

Capacity management and sizing overview for SharePoint Server 2010

http://technet.microsoft.com/en-us/library/ff758647.aspx