Same here, Dynmap is not working either with the latest build.
2013-02-06 23:56:08 [iNFO] [bukkitForge] Starting BukkitForge null-null(CB-Version: git-Bukkit-1.4.5-R1.0-b3000jnks (Really: BukkitForge for MC 1.4.7)).
2013-02-06 23:56:08 [iNFO] [bukkitForge] This server is running BukkitForge version git-Bukkit-1.4.5-R1.0-b3000jnks (Really: BukkitForge for MC 1.4.7) (Implementing API version 1.4.7-R0.1)
2013-02-06 23:56:08 [iNFO] [bukkitForge] Plugins are being loaded...
2013-02-06 23:56:08 [iNFO] [sTDOUT] Mapping loaded 2024 classes, 2184 fields, 3533 methods, flags 30
2013-02-06 23:56:08 [sEVERE] [Minecraft] [dynmap] Error finding net.minecraft.server packages
2013-02-06 23:56:08 [sEVERE] [Minecraft] [dynmap] Cannot find org.bukkit.craftbukkit.util.LongHashset
2013-02-06 23:56:08 [sEVERE] [bukkitForge] Could not load './plugins/dynmap.jar' in folder './plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.IllegalArgumentException: Error initializing dynmap - bukkit version incompatible!
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:204)
at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:307)
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:232)
at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:808)
at org.bukkit.craftbukkit.CraftServer.<init>(CraftServer.java:229)
at keepcalm.mods.bukkit.asm.BukkitStarter.run(BukkitStarter.java:46)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.IllegalArgumentException: Error initializing dynmap - bukkit version incompatible!
at org.dynmap.bukkit.BukkitVersionHelperGeneric.<init>(BukkitVersionHelperGeneric.java:114)
at org.dynmap.bukkit.BukkitVersionHelperCB.<init>(BukkitVersionHelperCB.java:20)
at org.dynmap.bukkit.BukkitVersionHelper.getHelper(BukkitVersionHelper.java:29)
at org.dynmap.bukkit.DynmapPlugin.<init>(DynmapPlugin.java:115)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:200)
... 6 more
2013-02-06 23:56:08 [iNFO] [bukkitForge] Loading PostWorld plugins...
2013-02-06 23:56:08 [iNFO] [bukkitForge] Going to load perms file: permissions.yml
2013-02-06 23:56:08 [iNFO] [bukkitForge] Server permissions file permissions.yml is empty, ignoring it
2013-02-06 23:56:08 [iNFO] [bukkitForge] Loaded plugins: