Let's say this is a true render of it, I'd hope the vents along the bottom are correct as they look like those on my Late-2013 Mac Pro, and I like those. It would be in keeping with the MBP design language to have four feet underneath, too, and the "Mac mini" name on the base like on the MBPs.
The power supply is built-in, so on the back there's a pill-shaped vent horizontally across the bottom.
Taking something else from the 2013 Mac Pro I'd like the locking switch there, which when unlocked allows you to lift the top case off, revealing just space for some extra SSDs. I wouldn't expect to see the motherboard, just a black cover over it.
Because you can lift off the top I wouldn't expect wireless charging on there, unless they include the coils in the top and have power connectors that click together when the case is closed, kind of how the power button on the top of the 2019 Mac Pro only works when the case is properly closed.
I'd expect the ports to be 6 x TB4, 4 x USB-3, 1 x Gigabit Ethernet (option to upgrade to 10Gb), 1 x normal power lead (not the magnetic one from the 24" iMac), 1 x HDMI, 1 x headphone jack.
CPU? Likely 1 x M1 Pro/Max. I doubt it'll be a dual-CPU machine. It might be an option, but not cheap as you're basically doubling the RAM.
Price-wise, hmm... Current Mac mini 512GB SSD, 16GB RAM is £1,099, so to add all the ports and the newer chip(s)... £1,499 for 512GB SSD, 16GB RAM, and the lowest M1 Pro available (8-core CPU, 14-core GPU). That, in the current 14" MBP is £1,899 so that's £400 less for the lack of screen and some additional ports, and £400 more than an existing M1 Mac mini?
(I am usually wrong on these things, but the joy is in guessing.)