I don't think we're in spoiler territory yet. Although it is possible that Chris Ryan will one day write a different book I suppose. Or that someone will do a really out there adaptation
I don't think he'll win any prizes for contribuions to literature, true. But I guess he writes about what he knows, and does quite well out of it I imagine and if his adaptations make TV like I saw yesterday, then I'm all for it.
Can't see him reinventing himself and doing a Merchant-Ivory peice. No reason he should either.