Since the release of PVKII on steam there have been a number of custom maps which have been released to work with the new version.
If you are interested in how to map for PVKII here are two useful links:
http://forums.pvkii.com/index.php?showtopic=9945 (Setting up Hammer to recognize PVKII on steam)
http://forums.pvkii.com/index.php?showtopic=6388 (Useful tutorials relating to many special features of PVKII and setting up gamemodes)
Here are all the great custom maps:
te_keep by Lord Trilobite: http://forums.pvkii.com/index.php?showtopic=4209
lts_sky_pirates by Lord Trilobite: http://forums.pvkii.com/index.php?showtopic=8040
pvk_float by Sheerlegs: http://forums.pvkii.com/index.php?showtopic=9704
dm_catacombs by Lord Trilobite: http://forums.pvkii.com/index.php?showtopic=10390
hg_boarded by Lord Trilobite: http://forums.pvkii.com/index.php?showtopic=7772
lts_inferno by Lord Trilobite: http://forums.pvkii.com/index.php?showtopic=9454
te_templepit by Lord Trilobite: http://forums.pvkii.com/index.php?showtopic=6628
dm_basalt_beach by Lord Trilobite: http://forums.pvkii.com/index.php?showtopic=6133
pvk_siege_longship by Mason: http://forums.pvkii.com/index.php?showtopic=9021
pvk_overlord by kow75: http://forums.pvkii.com/index.php?showtopic=9084
pvk_falls by Lord Trilobite: http://www.fpsbanana.com/maps/90079
pvk_trium by -AOD- Bruce Campbell: http://www.fpsbanana.com/maps/73250
pvk_gravedanger by Miggog: http://www.fpsbanana.com/maps/79115
Many servers are currently running many of these maps!