All of that is squeezed into a compact, understated all-aluminum body (in silver or black), replete with an overstated red dot that tells everyone your relative net worth. Like Sony and unlike Fujifilm APS-C models, it's mostly a menu-driven camera, with just a couple of dials to change settings.
The main features are an all-new 24-megapixel sensor and image processor, a big improvement from the TL's 16-megapixel chip. It can shoot mechanically at up to 7 fps and in electronic mode at 20 fps, capturing about 100 RAW images -- not too shabby for its class, especially compared to the original TL. Maximum ISO is now 50,000, again a jump up from before, and there are 49 focus points instead of nine. That's also nice, but AF performance is reportedly slow compared to stellar models like Sony's A6500.
Another big plus is 4K video. You can shoot Ultra HD resolution (3,840 x 2,160) at up to 30 fps, 1080p at 60 fps, or in "slomo" 120 fps mode at 720p (there are no headphone or microphone ports, unfortunately). Leica never said whether it's reading the entire sensor or line-skipping, though, and since video has never been its strong point, we'll reserve judgement until we get a better look at the quality.
Leica redesigned the TL2's menu system, "grouping menu items according to related functions, [so] the menu is now more clearly and logically structured." The 3.7-inch rear display also functions as a touchscreen, but for an EVF you'll need to buy the $575 Visoflex, the same model sold with the TL. If you want to shoot remotely or transfer images, the TL2 has integrated WiFi and a USB 3.0 port, plus the TL app (on iOS or Android).
Leica's forté is its lenses, and it has three primes and three zooms available for the TL system, including a Summicron-TL 23 mm f/2 ASPH ($1,500) and Summilux-TL 35 mm f/1.4 ASPH ($2,400). It's also compatible with full-frame Leica SL lenses without an adapter, and M-system lenses with one. It's now on pre-order in stores like B&H Electronics for $1,950.