For those who don't know who Boba Fett is, here's a quick rundown. He was first introduced in the Star Wars Holiday Special and then later in the flesh in The Empire Strikes Back as one of the bounty hunters hired by Darth Vader to track Han Solo. Although it doesn't mention in the The Empire Strikes Back, the two of them have a history together and it isn't exactly a good one.
Fett is later killed - apparently - in Return Of The Jedi when Solo knocks on his jetpack by accident and sends him flying into the Pit Of Carkoon where he's eaten by a giant monster called the Sarlaac. Pretty ignominious, but the Expanded Universe novels and comics (which are now no longer recognised as canon) had it that he got out of there pretty quickly and went rampaging after Solo.
The character was also in the prequel trilogy movie Attack Of The Clones, where his biological father - Jango Fett - was played by New Zealander actor Temeura Morrison. Boba was an exact clone of Jango and took on his father's armour after his death at the hands of Samuel L. Jackson's character, Mace Windu.
One of the biggest influences on Boba Fett's design - and likely the reason why James Mangold was hired - was spaghetti westerns such as A Fistful Of Dollars and Django. In fact, Jango Fett's name is an allusion to the character created by Sergio Corbucci and played by Franco Nero. Fett's visor on his helmet was meant to evoke Clint Eastwood's squinty eyes and the short cloak he wears is similar in style to the one he wore in A Fistful Of Dollars.
In short, Boba Fett is basically a Western character airdropped into the middle of a Star Wars movie - and Mangold's been directing Westerns pretty much since the start of his career. His first film, the hugely underrated Copland, was described by critics at the time as a modern-day Western and you can see all the influences in it. 2007's 3:10 To Yuma - which was an adaptation of a novella written by the great Elmore Leonard - starred Russell Crowe and Christian Bale as a ruthless leader of a band of criminals (Crowe) who's being transported to prison by a retired, one-legged rancher (Bale). While that film was a little bit of a misfire, Logan was by far his most accomplished work in Westerns and had people comparing it to Unforgiven, Clint Eastwood's swansong to the genre.
So, will Boba Fett be like Logan? Well, for one thing, you can forget about it being as violent as that as Lucasfilm and Disney are highly unlikely to have Boba Fett driving a knife through some poor git's head. Not only that, you had the incredible, lived-in performances of Hugh Jackman and Patrick Stewart propping it up and a great script from Scott Frank and Mangold as well. THR's report was updated to state that Simon Kinberg will be writing the script with Mangold as well, and just the general choice of director means that Lucasfilm knows what they're getting with this.
There is, however, another factor to this and its the current trend with Lucasfilm and the directors it hires. As evidenced by Solo, Lucasfilm has no problem dumping out a director and replacing them if they don't turn in what was originally agreed upon and if the work is falling behind, they've got no compunction about bringing on help to get it over the line - as shown in Rogue One and Tony Gilroy's involvement. Mangold has proven that he's able to turn a film without stress and his filmography is accomplished and experienced with major studio budgets. In the case of Gareth Edwards in Rogue One and Phil Lord & Chris Miller for Solo, it was either their first or second time dealing with them.
As previously reported, Alden Ehrenreich - who's playing the younger Solo - has signed on for two more movies as the character, so it seems likely he'll play a role here - along with Emilia Clarke's character as well. The other thing that makes this all so exciting is that Boba Fett isn't a morally upright character. In fact, he's pretty much a villain. Whenever he's shown on his screen, he's either near some of the most heinous characters in the Star Wars universe or he's trying to kill its heroes. Star Wars hasn't had a movie from this perspective, so it'll be interesting to see if they neuter or adjust him to make him more palatable, or if they'll let him be the bad-ass he's loved for.
Ultimately, what Boba Fett will look like will be determined by a range of factors, but given James Mangold's familiarity with Westerns and anti-hero stories, you can expect something not entirely unfamiliar - but definitely different.