Second - there's nothing coming down the pike hardware wise that will really make a difference. All the flagship CPUs and GPUs have already been released - and the next generation will probably be just rehashes of the current generation. Intel's Haswell is supposed to be using a dramatically new manufacturing process but I'm guessing it won't be at least a year before we see anything.
There is nothing, I can see, that is likely to change the NATURE of the demands, between Crysis 2 and 3, although, of course the LEVEL of demand may change. The best system, for 2, is likely to be best for 3, subject to equipment improvements. It wouldn't be in game designers' interest to change the balance, drastically, as they want fans of 2, to want to get 3, rather than be put of by the thought that one system can't run both.
Both nVidia and AMD have new GPUs, due in 2013, and Intel have Haswell, and AMD Steamroller, in 2013. None of them are due before Q2, so what you see is basically what you get, for Jan 2013.
Of course, it depends what you have now, as to whether a part upgrade, in Jan, and further part upgrade, later in the year, may be a good option.