it makes sense for them to release it that soon, they need to release the console within 24 months of the first console to have any real chance of being the top selling console of the generation, but the closer the launch's are, the easier it is to overtake the other systems

I wouldn't be to surprised.

I see whre you are coming from, but you didn't mention one thing, development costs. This will be the bottleneck that will stop devs from making games that look as good as Epic's Unreal Engine demo. Several studios have closed down this gen due to high costs. Only the biggest devs, will even take a chance. You are right about 1080p/60 fps being the norm for next gen though.

To respond to the OP and some posts made in this thread:

1. 18 months will likely translate to 2-2.5 years given delays. Holiday 2013 wouldn't be too surprising at all.

2. No need for an upgrade because 1080p is the best we'll get? Few, few games can manage 1080p on ps3/360, with a majority actually running below 720p, meanwhile PCs have been capable of running games at resolutions well above 1080p for years. New consoles would provide significantly better image quality than current consoles if released today, let alone two years from now.

3. 60fps will never be a standard. Never. There will always be developers willing to sacrifice framerate for other graphical effects, and they'll probably always be a majority.

Some people here are talking about Microsoft holding off with Sony. Well rumor has it Microsoft will unveil their new console at E3 2012, if that is the case then this rumor from Sony sounds way more logical. The fact is Sony is obviously watching Nintendo and Microsoft and they aren't stupid they won't let either company have to much of a head start. Also power wise I am sure Sony has some insight into how powerful WiiU and Nex-Box are and I'm sure they are ensuring PS4 will be a competitive product.

Sony aren't stupid, they won't launch too far behind the competition and they won't launch at a drastic price compared to the competition. I'm sure they are most interested this generation in competing right out of the gate!

Sony tried to launch with MS last time.. also lets keep in mind - Unveiling ( a console at E3 ) is one thing... Launching is another ! 

I think Sony and MS 'both' unveiled about a year before they launched PS3/Xbox 360 .. Actually since the PS3 got unintentionally delayed by Sony ..the PS3 was launched almost 2 yrs after it was unveiled ....

Damn it should last more than 10 years!

one thing is for sure. sony will definately not allow microsoft a head start this time. they will both release around the same time.

My question is: Will it be enough?  

A 300 dollar console in 2013 still doesn't sound powerful enough to last till 2020/2021, and if they don't make it price competitive from the get go they'll be dreamcasted by the competition.  I'm starting to wonder if Sony will be the middle man out next gen...

What you said is available for all consoles and not just the PS4.