There's no way they'd spend more time developing for the PC above the absolute minimum. And even if they did release a patch with more graphical features, they'd charge money for it.
Crytek didn't charge for their DX11/texture patch.
And about the screenshot, it would take a beast of a rig to achieve those graphics, but it's real. Here are some more:
http://gsnszw.bay.livefilestore.com/y1pVsptOcjOf33qZRRnqkEMnKMO2hXKb7d6JPmdxwEs9PdM4lXs02ApnARYwmCrguZWiW2617BYoZ-BggbUvglRgmZcJAgs8bS-/2axca.jpg?psid=1 (you can sort of see the same ground textures around the train tracks)
http://gsnszw.bay.livefilestore.com/y1pEYozZrEt3kgj21nOCnfrQBKFQEMr64tBDBCEInkmJaov1wnMQ3gIB-lqAoQXEWIUdteplGz6MzT_OTV8JVLIKGC1wtfjkFFU/65yib.jpg?psid=1
http://gsnszw.bay.livefilestore.com/y1pSfwoR-TT8MJBsReyvPcO4ZPMENNnhITOjQF23qOI2B21GRKueV380E3BYIGTMS9bXPudpufW19opV0vMoBODoa53P7ZnanHJ/crysis_tod_art_339kdpl.jpg?psid=1
http://izit.org/sites/izit.org/files/imagecache/Standard_View/sites/default/files/Crysis_7425.jpg
http://www.theoldbreed.com/imagehosting/68495b11b78f360.jpg
http://www.pcgameshardware.com/screenshots/original/2008/05/cvr_8.jpg