I saw this forum today (http://forum.unity3d.com/viewtopic.php?t=57692). In it, some one suggested that only animations with bones can be imported into unity 3d, is this true?
No. Every object that is keyframe animated can be imported (in most applications, you can "bake" non-keyframed animation to keyframes). This applies to non-rigged geometry as well as geometry with bones, as the bones are just keyframed objects.
If you read a little further to what you read, there is evidence that not only bone-based animation can be imported.
What is true is that you cannot, currently, import point-cached animations (animations with animation data stored per-vertex).