Ok, I think I can shed some more light on what seanfromcolumbus said about the latest 10.7 release. Under snow leopard (10.6) these were my ping results (as previously posted). Obviously very erratic and comparable to everyone elses results.
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=116.953 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=37.431 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=266.030 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=187.215 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=108.647 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=30.441 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=258.845 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=180.366 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=5.391 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=22.983 ms
--- 192.168.1.1 ping statistics ---
10 packets transmitted, 10 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 5.391/121.430/266.030/92.881 ms
Under 10.7 preview 3 there was a massive improvement (see below), but still not as consistent as you'd expect sitting 2 meters away from an airport extreme. Under windows 7 it is consistenty 1ms on the same machine.
ping -c 20 192.168.1.1
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=6.589 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=5.270 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=6.718 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=9.371 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=5.189 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=6.055 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=6.430 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=5.859 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=5.531 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=6.551 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=5.731 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=2.786 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=5.769 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=6.226 ms
64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=1.569 ms
64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=6.765 ms
64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=10.522 ms
64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=4.800 ms
64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=10.316 ms
64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=5.474 ms
--- 192.168.1.1 ping statistics ---
20 packets transmitted, 20 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.569/6.176/10.522/2.062 ms
As I and others had previously had better results while streaming a video or some other content I tried that as well, streaming a video while pinging under 10.7 and found this. Not quite 100% consistent but pretty good. So it seems that there have been some improvements made the wireless is still not functioning to it's capacity in general as the difference between the 3 sets of results shows. Hope that sheds some light on it...
ping -c 20 192.168.1.1
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=1.397 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=1.427 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1.457 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=6.264 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=1.400 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=1.849 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=9.598 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=1.483 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=1.596 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=1.470 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=1.383 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=1.634 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=5.675 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=1.485 ms
64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=1.469 ms
64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=5.080 ms
64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=1.459 ms
64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=4.829 ms
64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=10.402 ms
64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=6.182 ms
--- 192.168.1.1 ping statistics ---
20 packets transmitted, 20 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 1.383/3.377/10.402/2.833 ms