The new smartphone is currently listed as "coming soon" over at Orange's website. There's no mention on when exactly the network will launch it, but it's probably going to happen in January (when O2 and Vodafone will release the handset, too).
Running BlackBerry 7 OS, the 9790 features a full QWERTY keyboard, 2.4 inch touchscreen display with 480 x 360 pixels, NFC, Wi-Fi, HSDPA, GPS, 5MP camera, 768MB of RAM, 1GHz single core processor, and 8GB of internal memory.