Big players on the front of the motherboard include:

Samsung KB100L00WM-A453 4Gb (512 MB) of mobile DRAM which contains a 1 GHz Intrinsity Processor in a package-on-package configuration, according to the fine folks at Chipworks.

ST Ericsson's THOR M5730 HSPA+ Thin Modem

Bosch Sensortec Accelerometer

Maxim MAX8987 DC Power Management

ST Ericsson GNS7560 Single Chip GPS Solution

Here's an ultra high-res version of this image, in case you want to inspect the board thoroughly.