Being serious, it's a complex situation for all three, and a risk for all three when they launch, although I expect Nintendo to go first this time, and by quite some margin. Nintendo also probably have the largest task in that this time it has to be an all new console from foundation in terms of its innards. Microsoft also have a problem in that they have a funny GPU design, and a CPU that's only ever been used in the XB360. Sony have a strange CPU, but one that is known to be highly scalable, own the design of it, and have a GPU that doesn't really do anything odd at all and could be replaced with any off the shelf PC GPU derivative. They could probably launch tomorrow with something, or they can react very very rapidly due to the scalability of their hardware. For example, Microsoft announce something, it isn't then complicated to add an extra Cell, take one away, etc.
If Sony do not launch PS4 with Cell CPUs and a standard PC style GPU I'll let Elvis suck my cock. 100% backwards compatible and uses the exact same tool chain as PS3.