So according to the latests leaks the next generation Mac mini would come in the first half of 2020 along the release of the new Comet Lake S Intel chips. Source:
https://cdn.wccftech.com/wp-content...ce-Lake-Comet-Lake-Tiger-Lake-Rocket-Lake.jpg
The recent intel leak shows the following chips suitable for a Mac mini refresh: i3-10100, i5-10400, i5-10500, i5-10600, i7-10700, of which I think the 10100, 10400 and 10700 models (maybe a B versión of those) are the perfect replacements for the i3-8100B, i5-8500B and i7-8700B chips used on the current Mac mini. Source:
https://imagescdn.tweaktown.com/news/6/6/66560_02_intel-core-i9-10900kf-10c-20t-2ghz-499.jpg
So the specs for the next Mac mini would be the following:
Processor
SAME TDP of 65W on all CPUs:
CURRENT i3-8100B 3.6GHz 4-core 4-threads 6MB shared L3 cache
NEW!!!!!! i3-10100 3.7GHz 4-core 8-threads 7MB shared L3 cache Turbo Boost up to 4.4GHz
CURRENT i5-8500B 3.0GHz 6-core 12-threads 9MB shared L3 cache Turbo Boost up to 4.1GHz
NEW!!!!!! i5-10500 3.1GHz 6-core 12-threads 12MB shared L3 cache Turbo Boost up to 4.6GHz
Configurable to:
CURRENT i7-8700B 3.2GHz 6-core 12-threads 12MB shared L3 cache Turbo Boost up to 4.6GHz
NEW!!!!!! i7-10700 3.1GHz 8-core 16-threads 16MB shared L3 cache Turbo Boost up to 4.9GHz
Other less likely CPU options for the middle and base model could be:
-i5-10400 3.0GHz Turbo Boost 4.4GHz
-i5-10600 3.2GHz Turbo Boost 4.8GHz
Both 6-core 12-threads 12MB shared L3 cache
Memory
CURRENT 8GB 2666MHz DDR4 SO-DIMM
Configurable to 16GB, 32GB, or 64GB
NEW!!!!!! 8GB 3200MHz DDR4 SO-DIMM
Configurable to 16GB, 32GB, 64GB, … maybe more? we don't know yet until we see more of the memory specs of the chips
Storage
128GB PCIe-based SSD
Configurable to 256GB, 512GB, 1TB, 2TB
256GB PCIe-based SSD
Configurable to 512GB, 1TB, or 2TB
SAME OR base storage increase:
256GB PCIe-based SSD
Configurable to 512GB, 1TB, 2TB or 4TB
Graphics
CURRENT Intel UHD Graphics 630
NEW!!!!!! Intel UHD Graphics 730
Video Support
SAME:
- Up to three displays: Two 4096x2304 60Hz Thunderbolt 3 + one 4096x2160 60Hz HDMI 2.0
- Up to two displays: One 5120x2880 60Hz Thunderbolt 3 + one 4096x2160 60Hz HDMI 2.0
Thunderbolt 3 digital video output supports
- Native DisplayPort output over USB-C
- Thunderbolt 2, DVI, and VGA output supported using adapters
HDMI 2.0 display video output:
- One 4096x2160 60Hz
- DVI output using HDMI to DVI Adapter
Audio
SAME:
- Built-in speaker
- 3.5 mm headphone jack
- HDMI 2.0 multichannel output
Connections and Expansion
SAME:
4x Thunderbolt 3 (USB‑C) supports:
- DisplayPort
- Thunderbolt (up to 40 Gbps)
- USB 3.1 Gen 2 (up to 10 Gbps)
- Thunderbolt 2, HDMI, DVI and VGA
Gigabit Ethernet
HDMI 2.0
2x USB 3 (up to 5 Gbps)
Jack 3,5 mm
Communications
SAME:
Wi‑Fi 802.11ac
IEEE 802.11a/b/n compatible
Bluetooth 5.0
Gigabit Ethernet 10/100/1000BASE-T (RJ‑45)
Configurable to Ethernet 1/2.5/5/10Gb Nbase‑T
Size
SAME:
Width: 7.7” (19.7 cm)
Height: 1.4” (3.6 cm)
Depth: 7.7” 19.7 (cm)
Weight
SAME:
1,3 kg
It's possible for Apple to release a slightly updated version of the Mac mini with better 8th generation Intel Core processors similar to the recent MacBook Pro and MacBook Air updates. However if they were to I guess they would have already done it along the new MacBook updates from this week, and it wouldn't make sense for them to do it later in the year for the proximity to the next year revision of the Mac mini.
So unless Intel is to release the new leaked chips before the leaked roadmap shows, the new Mac mini is to come at early 2020.