I am always on the lookout for new software. Today I happened to find a couple free Terrain Generator. There not as good as Bryce but they are free.
Nem's Tools - Terrain Generator Can export this one as an OBJ file and import in Blender.
Terragen Have to export as a Lightwave file but still can import that file into Blender.
The reason I say there not as good as Bryce is cause their square meshes where Bryce can be shaped. But still since there free...