How has no one chimed in to say that speedhacking is impossible in RunUO? It's been impossible in RunUO since 2003. Ping and computer speed absolutely contribute to your max run speed in this game, but that's not speedhacking.
The RunUO server limits maximum run speed-- if you're unhappy with the maximum speed that people playing on newish computers with awesome connections can achieve, then the admins could totally tweak that maximum speed number.
Off the top of my head, I seem to recall the max speed being 100ms per step. That does not mean that if you ping 100ms, you have max speed because there are maaaaany more packets than just your movement requests going back and forth between you and the server. And most of those packets are significantly longer than the 32-byte ICMP PING packet that windows sends by default, so just running "ping login.uoforever.com" isn't 100% accurate. Anyway, though, pinging ~100 (even though 100 is pretty good) is radically different from pinging ~10-20.
Then why have several users been banned/jailed for it?