Things to consider for implementing and deploying SharePoint RBS

1. RBS stands for Remote Blob Storage.  The premise of RBS is that it is much faster to render large BLOBs( Binary Large Objects) from a file system rather than from a database (such as the SharePoint Content Database).  Therefore, by moving this content out of the SharePoint Content Database, you not only shrink the overall size of your content database, you are able to also move that content on external file stores such as SAN, NAS or DAS.  You can read more about SharePoint RBS here:  http://technet.microsoft.com/en-us/library/ee748649.aspx
2. As of SharePoint 2010, the functionality for providing this capability actually stems from SQL Server rather than SharePoint itself.  This was not the case with SharePoint 2007 in which this functionality was provided via EBS (Enterprise Blob Storage).
3. Since the functionality is provided through SQL Server, a prerequisite for support RBS with SharePoint is to be running SQL Server 2008/2008 R2 Enterprise Edition (or Developer Edition)
4. There are 3 methods (essentially) for supporting RBS with SharePoint:
• Use the Remote Blob Store support provided with the SQL Server 2008 (http://www.microsoft.com/en-us/download/details.aspx?id=16177 )  or 2008 R2 Feature Pack (http://www.microsoft.com/en-us/download/details.aspx?id=16978 )
• Use a 3rd party RBS provider such as AvePoint DocAve Storage Manager ( http://www.avepoint.com/sharepoint-storage-manager-docave/)
• Use a 3rd party RBS provider such as Metalogix StoragePoint ( http://www.metalogix.com/Products/StoragePoint/StoragePoint-BLOB-Offloading.aspx)
5. The "sweet spot" for moving BLOBs out of the SharePoint Content Database ranges anywhere from 256KB to 1 MB.  That is to say, any content smaller than around 1 MB is likely to have better performance rendering directly from the database rather than a remote file store.  Files larger than 1 MB (especially significantly larger files) will demonstrate more of a dramatic improvement by rendering from an external file store.
6. The maximum file size limit for storing file content through SharePoint is 2 GB regardless of whether or not you are using RBS.  This is due to a 32-bit pointer limitation implemented in SharePoint 2010.  Therefore, if you intend to store files larger than 2 GB, you cannot surface this content through SharePoint directly.  However, if you do have this need, both AvePoint DocAve Storage Manager and Metalogix StoragePoint offer connectors which can display these large files from a remote file share and display them in SharePoint.  That is to say, the BLOB content is never uploaded and managed directly through SharePoint (has to be managed from the remote file system directly), however, it can still be displayed in SharePoint.
7. Once you begin using RBS, this will also have to be factored into your backup and recovery strategy. Since all BLOB content is no longer being stored in the SharePoint Content Database, you will additionally have to make sure that you have backups of your remote file storage data in conjunction with your SharePoint Farm settings and databases.
8. An advantage of using either 3rd party RBS solution is the ability to support multiple remote file storage mediums including cloud storage such as Amazon EC2 and Windows Azure.
9. Both 3rd party RBS solutions also support the concept of "tiered storage".  This allows for less frequently accessed content to be moved to cheaper storage as the content ages or is less frequently accessed.
10. Both 3rd party RBS solutions support the capability to use RealTime Storage or Scheduled Storage through the use of configurable rules.  RealTime storage moves the BLOBs directly to the remote file store as soon as they are added to SharePoint whereas Scheduled storage first stores the content in the database and then later moves it out to the remote file store at a later point in time based on the set of rules applied and the corresponding schedule.  As you can guess, however, Scheduled Storage will require greater maintenance on the content database.
11. Both 3rd party RBS solutions provide a capability called "Orphan BLOB Retention".  This essentially manages what content remains on the remote file store when the content is deleted from SharePoint.  A deletion in SharePoint would thus result in "orphaned BLOBs".  That is content which continues to exist on a remote file store, but no longer has a corresponding pointer in the SharePoint content database.  These solutions can either delete the content from the remote file store or retain the content based on a set of configurable rules.  
12. Both 3rd party RBS solutions provide the ability to encrypt the content on the remote file store.