if you expect the average user to be able to upload at 8Mbit, try moving to somewhere else, like the future
most users have 256k up, the number with faster upload is increasing but still the majority have 256k with nearly all having less than 512k (very few ISPs have more than 512k up on the bottom package, which is where most users are)... they will also have multiple slots open as well
if you assume the winmx defaults of 6 slots and the common speed of 256k then you'd expect to get 5k/s... although in reality i've found 10k/s is about the most common (probably because i go for people with slots free, meaning fewer slots to share the bandwidth over... heh) of course you get a fair few faster but very few slower, although average speeds do of course depend on what you're trying to download
