OK, here's the update.
The latest predicted on-sale date from Denon - for both the DVD-3800BD (£1700) and DVD-1800BD (£600) Blu-ray players - is the last week of November.
Sadly, Denon don't expect to get us review samples much before that on-sale date. Rest assured that they'll be a review priority, and we'll get our test verdicts to you ASAP.