As notacheese mentioned, it won't integrate with your PBX. That would be a great place for third-party development, though! I'd be enthused if Cisco would license the technology and make something like that to integrate with my CallManager system.
In terms of managing workflow, I think you're over-complicating this. Workflow management implies monumental gains in small incremental gains or larger gains. Unless you get hundreds of voicemails per day, you probably spend less time listening to voicemails than you do brushing your teeth. Unless you're the CEO of General Electric, your schedule probably isn't
that busy...
But yeah, it saves time - and most importantly, it's really, really convenient. You would probably love it if you had it.