Now I do not think that this is the case, with more legit rumors saying that quite a bit of this stuff will be added into 6th edition sometime next year. However I do not expect that these rules will just simply transfer over, I think some will be re-written to fit into the 40k game, flyers for example.
Please take with extra salt.
via liam0404
Currently, FW and IA supplements require the express permission of your opponent for use, and are 100% forbidden fro GTs. Now i've heard that with the next IA book, items from these books can be selected as if they belonged to your codex (e.g. a Wraithseer, or a Warp Hunter). I also heard that within the next year, they are looking to print IA in multiple languages - and that this would make these items legal for tournament play.
Kilkrazy
There's a rumour that Cities of Death, Planetstrike, Spearhead and Apoc all going to be made 40K legal at the same time as the FW stuff.