NIS recently opened pre-orders for a UMD version of Holy Invasion of Privacy, Badman! They say that pre-orders need to meet 1,000 or it won't happen, but I'm not entirely sure of that - they'll charge you right out the gate, not when it ships, so it seems to be a reasonably done deal. (Unless it's some kind of restriction with their e-commerce site - NIS hasn't exactly had the best track record with not screwing up lately.) I'm definitely going for this, because I immediately lost interest in the localized version once it was revelead to be DD only, but it more or less brings up another concern that I suspected - NIS had problems with retailers stocking the game, and going for PSN-only was the only way to get it published.
This isn't technically the first time this has happened. Nintendo published Elektroplankton as mail-order only for awhile, although it was eventually released in limited quantities to Gamestop. Same thing with the Korg DS synthesizer. Agetec also released a party game called LOL, only available through its website, although since it's essentially a glorified Pictochat.
But these are all "non-games", more or less. A couple of other published games have had troubles penetrating into retail. Atlus' Steal Princess, for example. You won't find it at Gamestop - the only place you'll find it is likely on Amazon. Same deal with Aksys's republication of Jake Hunter. Its original release was famously botched, with cut content and a lousy translation. Aksys reconciled by releasing it again, with a new translation and everything restored - except Gamestop won't stock it either, especially since they still have new copies of the original release rotting on the shelves for $15. Why did Gamestop have so little faith in these titles in particular? Jake Hunter is easy to understand, but why Steal Princess? It certainly didn't get great reviews, but it's no worse than any other middling RPG that's come out lately. Maybe they got burned on stocking The Dark Spire?
Not knowing the ins and outs of video game retail buying, I don't know if this has been a persistent problem throughout the ages. Most of the time the blame for games not getting localized falls either on the publisher, or the console manufacturer not approving them. Now with the possibility of retailers not stocking games, there's a third wrench in the works. Given that we're already seeing excellent titles like 7th Dragon (as of current) passed over for localization, it's fairly troubling. If nothing else, it's probably time to break out the Japanese coursebooks once again.