According to car and driver the 2011 cayenne will retain its off road prowess(a great deal of sales are in the middle east). It will however manage to shave 440lbs or so(more aluminum). They report 0-60 numbers that are not seemingly aimed at one-upping the x5 C & D reports 4.5 for the turbo, probably a conservative estimate. This means the NA motor probably falls in the 5 second range. The good thing (imo) is that it will receive the much better looking panamera style interior. Link if your interested in the prototype drive article.
2011 Porsche Cayenne - Prototype Drive - Auto Reviews - Car and Driver