With the release of Bloodborne, MGSV, Type-0 and Dragon Quest Heroes, I think it actually has a chance of catching up to PS3. Fingers crossed. If FFXV releases this year then all the better.
PS3 sold 1,180,000 units in the next full year at this point in time. PS4 would need to sell 1.4m to catch up.
Actually, I find this interesting so I'm going to open a new thread about this.
PS3 sold 1.2 million in 2007 and 1 million in 2008 in Japan. I think PS4 will fly past when it gets some proper games. Alligned launch sales is a little hard to compare though since PS4 launched in March. But i expect PS4 to easily do more than 1.2 million in 2015.