I'd love to see PM add proper OCN (original called number) packets for call forwarding, so that third party voicemail services (like YouMail) could be used, for Visual Voicemail/forwarding voicemail to email. I checked with the mods, and apparently this is intentionally disabled, so I figured I'd throw it up as a public lab idea.
As a workaround I've just setup a freephoneline account, and I'm using that to forward voicemails to email... But I do prefer Youmail's system of having a visual setup. I don't prefer it so much that I'm willing to pay for their premium service (which gets you a dedicated voice mailbox number) though. 🙂