It's a bit difficult it seems to trace back exactly when systems were unveiled, especially for the pre-internet era systems, but I could find dates for the PS2, PS3, Xbox and X360 and for these four, the delay between the unveiling and the launch has been a year or more, except for the X360 that was rushed out 6 months after its unveiling to replace the money hemorrhaging Xbox. Considering how both systems still perform, and that all new home consoles launch in North America between September and November, falls of 2014 seem a lot more plausible than your scenario, unless one of the two will try to leapfrog the other (even if launching first is certainly not a guaranteed win strategy).