I know many folks will start thinking straight after reading the subject: "use SnapManager for SharePoint!" - this is not gonna happen for some non-technical reasons, so yes, I'm asking about SnapManager for SQL specifically.
I think (correct me if that's not the case) that external BLOB will be simply ignored / not backed up, whilst SQL databases themselves will be properly backed up. I also think that this gap can be closed by creating post-job script, taking a snapshot of the BLOB - not very elegant, but should work?
Okay, just found out that in our particular case "the EBS provider will be the FILESTREAM option of the SQL Server 2008R2".
Following on that, SMSQL 6.0 IAG says:
"Filestreams are fully supported by SnapManager for SQL Server, and filestream objects configured within SQL appear in the SnapManager for SQL Server GUI. If you have a database that includes filestream objects, SnapManager for SQL Server can back up and restore the filestream objects along with the database."