Guild's get spammed en-mass in icecrown global chat, and if you put everyone spamming that crap in global on ignore then suddenly global chat is actually quite dead and can use a lower than 45 second cooldown.
Make a new chat channel for:
1). Character trading
2). Guild recruiting. Theres a guild recruitment channel that warmane for some god knows what reason made players in guild unable to actually see, therefor making ONLY guildless players advertise the guild's they're not in....... y'all see how redundant this one is?