Rage3D are ATI fans, so they'll say that useless, crappy features ATI got and nVidia doesn't are "the greatest thing ever".
nVNews is a little like that too, in my opinion a little less ( because nVidia does less crappy things probably ) , but that's not the point here.
PS 1.4 is ONLY supported in the Radeon 8500 and Radeon 9000. The Radeon 9700 and 9500 supports 2.0 ( and that means it also supports 1.4, but that's not so important to mention )
PS 1.4 being not supported by nVidia ( they say they've yet to see an effect needing 1.4 ) , very few developers use it.
In other words, no, GF4s do not support PS 1.4, but it's ridiculous to want that because nearly no games support it.