According to Pocketables, the xpPhone is now available for preorder. No price so far and no details on the speed of the AMD CPU but the rest of this doesn't look bad. I wish the N900 had gone with the larger screen and enhanced keyboard.
400g weight ? Careful with that, you might knock yourself out if you try to answer the phone too quickly
If all I wanted was a phone I could get a N1661 which weighs 100g less than the N900, although this is offset somewhat by the weight of all the cash I would still have in my pocket.
Being old, I remember the original Motorola cell phone which weighed nearly 800g. Carrying 400g and even holding it to my ear does not seem to be that big a problem given the offsetting benefit of a bigger screen and keyboard. Besides, with Bluetooth headsets, I don't need to take my phone out to answer calls.