What you might have heard is that when Adobe releases a new version of LightRoom or Photoshop, they immediately stop issuing updates to support new cameras with previous versions of these products. In such a situation, you can use Adobe DNG Converter to convert the newer raw files to a form (a .dng file) that can be read by older Adobe raw conversion software. However, LR3, being the current release, supports existing cameras, including the ones you mention.