SSIS package to backup all Analysis Services databases on one instance
Here is SSIS packaga that creates backup for each database in one SSAS instance. You can specify backup folder and server name by passing SSIS package variables through command line:
dtexec /FILE "C:\DTSX_Scripts\DWBackupOLAPDBs.dtsx" /Set \package.variables[BackupLocation].Value;c:\NewBackupLocation\ /Set \package.variables[SSASServerName].Value;NewSSASServerName
Use it at your own risk.