I recently saw this (yes, off SlashDot, so sue me)
"Windows XP SP2 limits the number of possible TCP connection attempts per second to 10 from an unlimited number in SP1. This can affect performance on server and P2P programs that need to open many outbound connections at the same time."
Uhm, so yeah... before I consider "upgrading" to SP2... how can I be sure this won't affect my BitTorrent and gaming experience? And if so, how to disable it?