I spoke to Michael Dutton today and he wanted me to relay that if any of the outstanding D-V shipments never show up, they'll replace them free of charge.
GOS, I feel particularly bad for how long you've waited, given how big a part of QQ your exuberance for surround music in general is. Just from personal experience, surface mail from the UK to North America can be unpredictably and agonisingly slow - I had some vinyl sent from the UK last year and it took nearly 60 days to arrive. I know that doesn't make waiting any easier, but I suspect your discs are going to show up eventually. I don't know how convenient going to your local post office is, but it might be worth popping in just to make sure you don't have any undelivered packages sitting there. I've had that happen where the package is at the post office, but the delivery slip notifying me to collect never made it to my mailbox.
I obviously can't say anything about D-V's future plans at this point, but between here, their facebook page, email requests and suggestions from amateur know-it-alls like myself they definitely have their finger on the pulse of what people are after, both in popular and classical music. They may be relatively new to SACD, but they've been doing CD reissues for 20 years now so they know what they're doing, both in terms of the quality of their product and the titles they're choosing to release. I think we all have quad albums we'd like to see them release, but they have to strike a balance between 'dancing with the one that brung ya' (ie the customers who got them to where they are now) while also carefully expanding the scope of their quad releases, as paying to license a title that doesn't sell or releasing a title that leaves them with hundreds or thousands of unsold copies does no favours to anyone. They also seem to have a keen sense for finding hidden gems, and I think the positive reviews of the Kostelanetz and Legrand discs - albums no one was asking for - bear that out. So who knows, maybe your next favourite quad SACD will be one you didn't even know you wanted.
A few pages back someone was asking if these releases are remastered or flat transfers - they're definitely remastered, and beautifully so. I haven't done any technical analysis on the SACD layers, but the CD layer of the Tower Of Power disc is DR14 (compared to the old 1993 Sony/Columbia release, which was DR13) and the Main Ingredient CD layer is similarly dynamic so if there's any compression being used in mastering it's minimal at most. The Penguin Guide to Classical Music on CD called Michael Dutton "the supreme magician of CD re-mastering" and I can't argue with that at all based on what I've heard. He seems to be bringing the same audiophile grade mastering at discount price release philosophy to his non-classical quad releases.