Well if you'd bought a GTX at release this wouldn't hold true, because it's been a year and only now is something 'just round the corner'. If you buy new gen tech on its release you are effectively maximising its useful life, assuming you don't buy every new increment of performance improved hardware that comes on the market.
i think thats the point he was trying to make, that if you wait for new hardware you should buy it on the date because the longer you wait the more chance there is of there being something new around the corner
i am in a similar prediciment but to be honest there is never a truly good time to buy technology because it is constantly changing but i personally will love my new set up because i have been using an old system with a ati x300 for the last 4 years.