One thing I think that's worth noting in general is that perennial franchises do not seem to have been affected by the hardware market contraction. Stuff like Monster Hunter on 3DS is selling as much as it ever did on PSP. The Persona 4 remake on Vita has already sold as much (+ digital) as the remake of Persona 3 did on PSP. Games like Mario Kart & Animal Crossing have seen a contraction in sales, but absolutely nothing that would be fatal to those IP's (they still sell extremely well and have time, through legs, to make up the difference).
To me, that shows that the market has simply changed. Many, many gamers have now gone to phones who would've bought a Wii/DS/PSP and possibly PS3 in the last generation. That doesn't mean that the gamers that are left aren't going to buy software. We may just see slight contractions from people who are buying the game on a whim; but I do still believe that the core market is in tact in Japan and buying games.
I just hope that the right combination of games can come along at once for the PS4 and convince the core that the console is worth buying, otherwise it may take a trickle of releases over time to get people on board and that may mean some early casualties which release before the value of the console "clicks" for a lot of people.
Stuff like Final Fantasy/Tales/Resident Evil/Yakuza/Metal Gear Solid/Dynasty Warriors/Gundam/Grand Theft Auto/Call of Duty/Battlefield all of which were PS4-exclusive (or multi-plat with XB1) would migrate the core audience over between them and as a result, I think they'd all see decent sales. Cross-gen; last-gen and a general lack of announcements is hurting that though and as a result, I don't think we're going to see decent sales for a long time from PS4. I think as a piece of hardware it won't sell exceptionally, but I still think software will start selling well on it one day. And I do believe the vast majority of those games will show up exclusively in one form or another - simply because they do the majority of their sales in the west (except for Yakuza/Dynasty Warriors/Gundam, which I think will turn up anyway because they always have).