If you can't decide between shields and .NET Gadgeteer modules, then we'd like you to meet FEZ Cerbuino Bee. We've taken the powerful Gadgeteer-compatible FEZ Cerberus and combined it with SD, power, USB Host, USB Client and XBee modules. Next, we added Arduino-compatible headers for shields and three Gadgeteer-compatible sockets for modules. Cerbuino Bee also has Xbee headers for ZigBee or WiFi XBee modules.

FEZ Cerbuino Bee's page:
http://www.ghielectronics.com/catalog/product/351

.NET Gadgeteer modules
http://www.ghielectronics.com/catalog/category/275/

Just like FEZ Cerb40, FEZ Cerbuino runs the same open-source FEZ Cerberus firmware, which is being developed by companies and community members alike. You are invited to join the project at https://stm32f4.codeplex.com/

At less than half the cost of EMX module, G120 SoM is an ideal choice for cost sensitive applications. G120 includes 120MHz. Cortex-M3 processor, 16MB of RAM, graphics support and a TFT LCD interface. Users will have 2MB available for their software application. G120 also includes our premium library with exclusive features such as WiFi support, PPP for cellular modems, USB Host, In-Field Update and Runtime Loadable Procedures (RLP) for running native code on the hardware.

G120 is in the final stages of testing. Available in the third quarter of 2012. Expected volume price is $30 each.
Please see G120 product page for more details http://www.ghielectronics.com/catalog/product/373

GHI Electronics is glad to announce over ten new module additions to the .NET Gadgeteer family that will expand the limitless capabilities of .NET Gadgeteer platform and .NET Micro Framework even further.

VideoOut Module: A display module that supports both VGA and Analog Video RCA output. Capable of outputting 320x240, 640x480, and 800x600 resolutions. Adding a 60" TV is a one module away.
http://www.ghielectronics.com/catalog/product/356

OBD II Module: This module will allow you to communicate with any vehicle that supports OBDII. With this module, you can read statistics from your car such as RPM, Vehicle Speed, Fuel Type/Level and much more.
http://www.ghielectronics.com/catalog/product/365

HD44780 Display Module: Adds a very simple and quick way to connect 16x2 and 20x4 character displays. We will also have one (or more) options with display included as well.
http://www.ghielectronics.com/catalog/product/358

MaxO Module: A chain-able output extender. Through a single S-socket a developer can add 32 outputs for each module added. Only 4 of these modules will add 128 outputs to a single socket.
http://www.ghielectronics.com/catalog/product/361

IO60P16 Module: A single socket from mainboard will add 60 inputs/outputs with interrupt capability. Also, 16 of these pins can be PWM signals. The signals with PWM are exposed on header-placement so it is easy to add standard RC servo motors. Adding 16 servo motors was never easier.
http://www.ghielectronics.com/catalog/product/363

RED LED Matrix Module (DaisyLink): The on-board 50Mhz Cortex-M0 handles all the timing ad drawing leaving the system free to control many of these modules with minimal system resources. Thanks to Gadgeteer's dasylink protocol, this is all handled automatically by the system.
http://www.ghielectronics.com/catalog/product/370

Load Module: Seven digital switches capable of 3Amp 30V to control motors, relays and even solenoids.
http://www.ghielectronics.com/catalog/product/364

IR Receiver Module with Remote:
http://www.ghielectronics.com/catalog/product/360

MicroSD Card Module:
http://www.ghielectronics.com/catalog/product/359

PIR motion detection module:
http://www.ghielectronics.com/catalog/product/357

RFID Reader Module.
http://www.ghielectronics.com/catalog/product/366

RS232 Module:
http://www.ghielectronics.com/catalog/product/355

There is more to come, we are just getting started.