Early leveling is a lot faster than it used to be, then it starts to taper off to a level every three or four sessions (for me).
Here is the breakdown for two different campaigns I've run for 3E (didn't keep track of my first 3E game this way):
Session 1: 850
Session 2: 750 Total: 1,600 (level 2)
Session 3: 1400 Total: 3,000 (level 3)
Session 4: 900 Total: 3,900
Session 5: 1600 Total: 5,500
Session 6: 2000 Total: 7,500 (level 4)
Session 7: 1100 Total: 8,600
Session 8: 1600 Total: 10,200 (level 5)
Session 9: 2000 Total: 12,200
Session 10: 1100 Total: 13,300
Session 11: 2000 Total: 15,300 (level 6)
Session 1: 500
Session 2: 800 Total: 1,300 (level 2)
Session 3: 1000 Total: 2,300
Session 4: 800 Total: 3,100 (level 3)
Session 5: 950 Total: 4,050
Session 6: 1500 Total: 5,550
Session 7: 750 Total: 6300 (level 4)
I think it is a good pace, especially for the early levels. I really like to start off at 1st level, though a lot of players get tired of fighting dire rats (heh). From 1st level, you can have more of a chance to develop the character as you go - at lower levels there are less options/power, and I think that vacuum of power can be filled with personality. But that's just me.