First of all,Ps3 have had some good games released already,like Street Fighter and White Knight Crhonicles (tho it was end of 2008)

Now Yakuza 3 came and seems like it sold 359k first day (tho some say it sold 239k or something)

Then we have Resident Evil 5 which most likely sells pretty much like Yakuza.

Then we have Final Fantasy Xiii demo and advent children Blu-ray bundles.

Then well Final Fantasy XIII late 2009 I think.

+ some other titles that we don't know yet.

2008 we had hmm Mgs 4 and Devil May Cry 4.

Final Fantasy XIII will outsold them easily.

And Xbox 360 and Wii doesn't have huge titles released that we know (well Monster Hunter 3) so its looking good for Ps3.

After RE5 there is the FFXIII demo and then the 2 FF games, nothing else announced for after that. Software sales are driving hardware sales and nothing of note is releasing on the PS3 after RE5 in Japan. If a price cut comes any time soon it will be the best year PS3 has in Japan, if not sales will slow.