Sorry, but I have read (or started to read) some truly horrible post-apocalyptic crapfests. Believe me, they were NOT interesting.
it doesn't matter what is thought of the genre 'these days'... even after you complete your ms, should you be lucky enough to snag a publisher, it will still take one and a half to two years from the date you sign the contract, before a book will be released... factor in all the time it can take to get you to that point [if you ever do] and you can see it will be several years before your brainchild of today will be read, so what is thought of the genre now won't matter, will it?
I wouldn't consider a post-apocalyptic story a genre, more a sub-genre. You must also understand the context. Many PA stories, particulary the ones in cinema, were a response to the fdear of a nuclear catastrophe. Since the Berlin wall fell, and we are no living in the grim fear of the reds, the whole sub-genre of PA seems terriblt dated. To me PA tales are cold war relics that lost a great deal of their power which was derived from fear of destruction. We have lots of stuff to be afraid of now, like global warming (Waterworld), epidemics (12 Monkeys), but not so much from nuclear holocausts. The PA subgenre still has its merits though, and some stories are meant to be in that setting, so for the sake of story, I say go for it and write it. As long as the fact that the planet is post-apocalyptic is relevant to the story, it deserves to be told. If you want a PA setting just because you think its cool, like some stories do, it seems superficial and silly.
Well, I'd imagine they will follow the template of No Country for Old Men and make it faithful. But yes the books strongest points can't really be transferred to the screen. But I'm excited about it regardless.