That's not true at all . SONY have made a ridiculous number of new IP for the PS2 and with the PS3 they've again done pretty well with new IP like Last of Us, Drakes, Infamous, Resistance, Little Big Planet, Motostorm to name but a few and SONY are going to launch new IP this year like with Puppeteer, Beyond 2 Souls .
It not so much to do with the death of SEGA and more to do with the death of the Japanese industry that's to blame imo . Japense developers no longer take risks and have been totally outclassed by Western corps these days thank to Japanse developers taking the safe and easy options and backing HH
Okay then, I admit that Sony have made new IPs consistently, but they never seem to stick with them unless they sell gangbusters (Even SEGA stuck by Panzer Dragoon when it didn't sell that well, although modern SEGA is just the same as Sony in terms of not supporting any of their other IPs, however they seem to support Yakuza well enough).
Parappa never really got a sequel (although it got a spin-off) and some of their IPs have died because of the lack of marketing, but it was a great concept. You also don't really see them support their Japanese division all that well (unless you count the Portable Teams, who have a great reign on what they do).
In regards to the Japanese Industry dying, I actually blame this on their refusal to adapt to the market trends. Call of Duty sells despite the questionable quality. Assassin's Creed sells despite being an even more stealthier game than Splinter Cell (both series are pretty similar) and you have those MMOs that make money such as Starcraft II, World of Warcraft and possibly Diablo (I don't care for any MMO...not even Phantasy Star Online).
What the Japanese are doing is trying to either copy the Western Studios (Capcom), attempt to HD their franchises at the cost of making a blander experience (Metal Gear Solid 4 and Final Fantasy 13) or just sticking to the handheld market only (Nihon Falcom) and ignoring the west entirely with the portable games (SEGA, Square Enix).
I don't mind the direction of portable games...but they won't localise the games as the west don't like portable experiences (and they damn should!), if the Japanese Studios can't adapt to HD, then they'll stick to handhelds...and even that market is shrinking and turning into freemiums to which they sadly won't survive despite the potential revenue they assume they will get (Breath of Fire 6).
I can sadly see gamers turning to PC (something I don't want to do...since I use my PC for research only and buying), to which Japanese Devs such as Nihon Falcom have adapted to really well! The consoles are the only place where the Japanese Developers are struggling with, and that is where most of the profit margins are, but they don't know how to manage R&D costs like the west can (well...the sensible ones anyway), so what we are seeing now is what I just mentioned. Less risks, trying to change to our way of making games (which doesn't work for most of them) and just overall lengthy timescales.
Of course, you can disagree with my points since we both have different ideas on where th e industry is going, but I hope you respect my thoughts on the industry as I will to you.
Anyway, I will end this saying that I love Dragon's Crown and wish Vanillaware all the success!