BBC Home Entertainment hasn't announced it to the press yet, but Amazon.com has a pre-order listing
for Last Tango in Halifax - Season 4
on DVD. The date shown at the entry is a long way off, February 7th
(!), and is clearly subject to change in the time between now and then. There's not official cover art there yet, just a placeholder image that doesn't mention the season so far. Amazon says it will be a 2-DVD set for $34.98 SRP. Stay tuned for updates!