Amazon has been busy overnight, unveiling its latest selection of hardware, which includes the Kindle Fire HDX 7- and 8.9-inch tablets.Certainly a step up for Amazon in all respects, with higher resolution HDX screens at 323 ppi (1,920 x 1,200) and 339 ppi (2,560 x 1,600) respectively for better viewing inside and out. Price aside, that and screen size are pretty much the only difference between the two models.Both models are lighter than previous incarnations, with a smaller bezel and cleaner lines, with more power within thanks to the 2.2 GHz quad-core Snapdragon 800 processor, 2GB RAM, an Adreno 330 graphics processor and Dolby Digital Plus audio. All of that and still up to 12 hours of use per charge - up to 18 hours if you are just reading.Other features include an 8-megapixel rear-facing camera able to shoot 1080p HD video and with LED flash, image stabilisation and support for panorama shots, a front facing camera with 720p HD shooting and a photo app for editing.There's also the option of 4G technology, Fire OS 3.0 (aka Mojito), which is loosely based on Jelly Bean, but with Amazon's finishing touch for the design (and what you can do - there's no Google Play access), Mayday, which hooks you up to an Amazon expert 24/7 and of course, everything you want Amazon-wise at your fingertips.Now, the frustrating bit. Amazon has launched the new tablets in a choice of sizes, storage options and with 4G options too, but so far, none of those have been confirmed for the UK. But if you are heading over to the US, prices start at $229. Hopefully UK prices will be confirmed soon.