Not yet. The game may have gone softer, but really, not yet.
IMO if Joe Smith is a capable PF in todays game Durant is too. However, I definately don't want to see KD being used as a post player, taking away most of his game which is his unique mobility, ballhandling and shooting ability for a player his size, 6-10 or so. If you look at Joe Smith (just using a him as a random example, Effekts post made me think about him) and compare him to Kevin I see two similarities: Both are 6-10 and they both have a very similar body type. Kevin Durant could play a similar game to Smith, just with a better jumpshot, quicker moves and better ballhandling.
Either way, Durant is gonna cause some pretty nasty matchup problems when he hits the league.