I was under the impression that this should be fairly straight forward to do.
It is, someone has already repackaged DSAudio, etc, for the Playbook under OS 2. I have 'side-loaded' them*.
Having only just bought my DS-411j, I haven't really enough experience yet to comment on how well they perform. Folks in the Crackberry forum have said they work well but they are phone apps and don't use the extra screen space available on the tablet. It would be good if Synology would release Android based Playbook versions.
*This means putting the Playbook in development mode and using a third party tool to install them. Very simple process