I think this is stupid for multiple reasons. But the most simple is that there are ways to make simple socket type connections for replacable memory that won't take more then 1-2mm of thickness compared to a directly soldered on board chip. Plus always the simple lay-down RAM designs current laptops use which take a whopping 8mm of vertical space... wee... I think greed is playing into this (forcing future upgrades due to non-upgradable of the individual parts) then the need to make it 'as thin as possible'. I'd much more prefer a 5mm thicker chassis for replaceable/upgradable memory, storage and batteries. For laptop/netbook/etc, these are at least my minimums of I won't purchase them. Heck, even my cellphone has upgradable storage...
OR - if they really want to make it as 'thin as possible', the other option would be to make a newer memory format. Something like RAM speed micro SD cards. Very tiny, huge size capabilities, but right now the SD cards are just to slow to be used for that purpose. But RAM doesn't have to be a huge 'stick' as they are normally today. There's millions of other possible options aside from soldering directly to the board. That is the lazy and IMHO, greedy way out.