The GTX 670 is a fantastic card without a doubt, it will play any game at 60fps today(without super sampling and AA maxed) at 1080p. At times it may dip below 60fps without a doubt, like any card will when things are really intense on screen.
Some games may be poorly optimized and not run very well though, but this card is nothing short of an excellent value for a single monitor at 1080, maybe even 1440p.
What you may want to consider is the following two options:
* Selling the GTX 670 on eBay in two years for a new card(so your paying 50% less on a new card minimum.
* Buying a second GTX 670 in a year or two for SLI when newer games are out.(This should give you another three years of high performance.
I have an ASUS GTX 670, ASUS has great warranties and customer support too. I am going to buy a second next year for SLI. The ASUS card idles about 30-36C depending on ambient temperature and 71-72c max during intensive game play; I have no manually overclocked it myself yet. This card does put off a ton of heat too, when I'm playing games, my ambient around me literally rises about 10c over an hour, lot of heat was rising from the top of my case.
In conclusion, the GTX 670 will last you 4 years easy by itself before you must to start playing on medium settings.