There's actually a premium edition of these, which has really sweet specs: 8 GB RAM (can be upgraded to 16 GB), a 256 GB SSD and an Intel Core i7-2620M CPU running at 2.7 GHz. All that, and it still retains the 10.1" screen, and it still weighs less than 1 kg.
Oh, and the battery life? You can choose between an "S" and an "L" battery pack; the former (included) gives you an 8-hour battery life, while the latter (sold separately as far as I can tell) goes up to 12 hours. And the weight stays below 1 kg even with the large battery pack if you don't count the protective sleeve.
Speaking of which, there is a protective sleeve, too: it won't quite turn the notebook into an ultra-rugged device, but it'll help guard against your notebook against small drops and other things.
The thing costs an arm and a leg, of course (the base price is 297,500 JPY, which is about 3770 USD or 2650 EUR), but still, it's really, really neat. I'd perhaps have preferred an ultra-mobile CPU myself (e.g. the Core i7-2677M, which only draws 17W instead of 35W) to extend the battery life even more, but nevertheless, the future has already begun.
Alas, it only did in Japan.