It doesn't look promising for many reasons, but in regards to your comment, Juliet is supposed to be beautiful*...
*and no, I don't mean anything to do with skin colour.
Yeah, I wouldn't have any desire to see it for multiple reasons, and not just because I don't live in London.
First, the leads are both problems, not just her. Tom Holland is just as miscast as Romeo as he was Nathan Drake to me. One can overlook that Juliet is described as having fair skin since there will be different renditions of this story that will lead to changes, so her race isn't an issue at all to me. The 1996 film has characters far removed from the Shakespeare play on top of the modern setting, but it worked, and I would argue that Harold Perrineau as Mercutio delivered a scene-stealing performance. Romeo Must Die was loosely based on Romeo & Juliet, and Aaliyah was believable as a Juliet-inspired character, so it can work fine with a black actress. But when so much of the story centers on Juliet's beauty, this actress just ain't it to me. Sorry! Based on what I have seen of her in Bad Education, I wouldn't say she is a very gifted actress either. When the two leads are horribly miscast, it doesn't inspire confidence in the rest of the project.
Then there is the rest of the cast, or lack thereof. Ten of the characters considered to be among the main characters of the original play are completely removed from this, right down to the leads only having one parent each. Kind of hard to be invested in a feud of families when they reduce a cast to a level that seems more like a neighbor squabble than a feud of two major families. That brings into question Juliet's beauty and the major family feud. Arguably the two biggest central plotlines of Romeo and Juliet. At this point, you should just write your own play.
But the worst offender is that Jamie Lloyd's plays simply look like pretentious high brow artsy theatre garbage to me. There is minimalist theatre because you are a small production that doesn't have a budget, and then there is having a budget you dump into one well-known star for attention and trying to sell the lack of costumes and sets as some bold vision. Then you need to hire an unknown cast to surround your one attention-getter that you have to cut so many main characters from. It is even being reported that Romeo will be a Capulet instead of Montague, and vice versa for Juliet (One would assume but who knows, maybe Incest is going to be a bold new vision in this version). Is there any logical reason that something like that needs to be done? No, you just change something like that for the sake of being as pretentious as you can possibly be because it is a bold new vision! So really, the casting doesn't even matter because this stuff doesn't change with perfect casting.
All that being said, this 1996 film divided people, and I like it. Romeo Must Die divided people, and I like it. The 2013 film divided people, and a lot of people found Hailee Steinfeld miscast, and I... well, I have never seen it, so no comment. The 1968 film was too far before my time to know the reception back then, and I just know there is a divide in modern times due to Olivia Hussey's age (plus her recent claims she was told nothing would be seen). But I enjoyed that version. 1968: Best film for purists of the original material. 1996: Best film for an alternate vision that doesn't manage to stray drastically from the original material despite such a big difference in the time setting. Romeo Must Die: Best film for people who are somewhat interested in the story but need more drastic changes, Jet Li kicking ass and a great soundtrack. So all the power to people who enjoy these Jamie Lloyd-style plays. I just really, really, really hate them.