There’s a little nugget in the last paragraph of this article on Belgacom’s deployment of ALU vectoring (in French), one that I wish had been more developed. Let me offer my own translation here:
One last point, Standaert also reveals that these networks will continue to be converted to all-IP: "In Knokke le Zoute in particular, everything goes via IP. This year, we already migrated 400.000 lines. By 2018, Belgacom will no longer have any classic telephone line." This means that the Siemens EWSD switches and the Alcatel-Lucent PSTN switched will finally all disappear. It should also free up a lot of physical space and allow Belgacom to sell even more of its buildings. By 2020, 30 buildings should be sold. Altogether, this should generate savings of 35 million euros.
I was astounded earlier this year to find out that the Australian NBN, despite the massive structural upheaval that it created had not been accompanied by a decision to phase out PSTN. Similarly the New Zealand policy makers, visionary though they might have been in establishing FTTH nationwide (or nearly so) and structurally separating their incumbent did not take this opportunity to dephase the legacy of PSTN.
Of course, this raises regulatory issues. In particular, what happens to voice regulation? An inclusive approach suggests that any VoIP service would become regulated, which may seem daunting and impractical. The alternative though would be that no voice services would be regulated, which seems somewhat dangerous.
I haven't spent enough time gathering data and thinking about this, but I do think it's going to be the major topic on the regulatory plate in the next five years. Stay tuned for more when I have more.