SQL Server "Katmai" 2008 will be good to Sharepoint !!!
Quoting from SQL Server "Katmai" 2008 White Paper:
The SQL Server FileStream object allows large binary data to be stored in the file system yet remain an integral part of the database with transactional consistency. This enables the scale out of large binary data to be managed by the database and yet stored on more cost-effective storage and file systems.
Sparse columns allow users to store object models onto relational data without undergoing large space costs. They also allows users to build complex content management applications with the underlying database.