WindowsPhoneMania.pl has managed to get their hands on some disassembly pictures and schematics  for the Nokia Lumia 620.

As one can imagine it does not reveal anything too dramatic for the lowest-end Windows Phone 8 handset, but one interesting feature is the presence of dual Microphones,  at points 1 and 10 in the above schematic, presumably from their position for noise cancelation purposes. This is interesting given that Apple is currently running a campaign for the noise cancellation microphone on the iPhone 5 (and presumably trying to convince people they unvented it), touting a feature present in what will be one of the cheapest Windows Phones.