You can probably expect an updated chassis around the time new CPU's are launched. They more often that not need an updated board so the manufacturers use that as a nice chance to refresh the chassis and overall design. I think the next batch of intel CPU's are due Q4 this year, thats just a guess at the moment as nobody but intel knows that info.
Overall I wouldn't worry too much about getting it because they're is always something new coming out just over the horizon, that's my thinking anyway. Whats your concern about buying a slightly older chassis anyway, is it just the performance? if so then the performance delta is likely to be fairly small.
Only thing I would like to be updated is the screen, perhaps to a slightly higher resolution or refresh rate. I find it strange that this model comes with dual graphics cards that are capable of playing intensive games at very high fps on ultra but only offer a 1080p 60hz display
However I do agree with what you are saying, I'm forever buying new tech and thinking about what the next model might be.