This sounds like an intriguing project. The Little Mermaid is a very fun film (and subverts Disney romantic cliches more than people give it credit for), but there are plenty of flaws with the portrayal of the protagonists, and the film is still dismissed as a story about a foolish teen who gives up everything "for a man". Therefore, I really support the idea of giving Ariel's story a big new remake. A live-action version could place the focus on Ariel's relationship with Triton and her coming-of-age, whilst still keeping the charm of the original. I really like the idea of giving it a firmly Caribbean setting, and a racially diverse cast could give this version a unique feel which expands on the most interesting aspects of the original...
I'm probably in the minority here, but I like the fact that the stage version tries to fix some of the problems with the original by giving Eric a complete character arc and allowing Ariel greater agency at the end. However, the film is pretty much impossible to translate to stage, leading to many of the unwise creative choices which made the theatrical version far inferior to its source material (The final battle in the original film was awesome, but the final battle in the stage version is almost completely devoid of action). With limitless CGI, plenty of water tanks, and the opportunity to film spectacular action sequences, the new film version of The Little Mermaid could improve on both the visuals and the story of the original Disney classic...