BUY NOW OR WAIT FOR NEXT MODEL?
This question will still be around another 100 yrs.
DSLRs are like any consumer electronic item nowadays, e.g. iPhone, iPad, mobile phone, laptops, etc.
There will be an endless list of features that will be available model after model (how else do the manufacturers keep making the huge profits? by 'teasing' the customers to keep chasing and buying their very latest models!.
Now back to photography, life cycles for film cameras were much longer. We used to keep the FM and FM2 for 15+ years and we were still very very happy with them. We bought good lenses and we continued to enjoy years of photography.
With the digital age, product life cycles become shorter. Still the question remains... are your just buying features or are you looking for a tool that (together with your input, your skills, your experience - yes some features are good to have) TO PRODUCE A BEAUTIFUL PHOTO.
So my suggestion to the TS is to buy what he needs for the kind of photography he does and start enjoying the journey. I can guarantee that every other week, there will be still more models with more 'bells & whistles'. The chase is endless.
One good note though - INVEST IN THE BEST LENSES YOU CAN AFFORD! These will transcend many body changes.
Hope this helps.