I herd rumors about Poirot being canceled before the last 6 books could be adapted so I emailed ITV asking and got this reply.
@ITV said: Dear Sir/Madam
Thank you for your email regarding ‘Poirot’. We have a new film yet to be broadcast The Clocks which was produced last year and ITV is in active discussions about doing more. Scripts are currently being developed but we are not currently in a position to announce new commissions. We are delighted with how well both Poirot and Marple are received by the ITV1 audience. I do hope you will continue to watch and enjoy many of our programmes.
May I take this opportunity to thank you for taking the time to contact us here at ITV Viewer Services. If we can be of further assistance please do not hesitate to contact us.
She didn't answer my question but she didn't say yes its axed and saying developing on new scripts seems like a good sign!