Over at the id Software website you can find a zip file containing all 34 maps submitted to the Quake 4 Community Map Pak contest. These maps will be narrowed down to 8-12 maps for the map pack following a voting process.
I'll reinstall q4 for this \o/
Never really gave online playing a proper chance with this one.
Great. =) Be sure to stick around, 1.4 is coming soon.