I wouldn't bet on it. The problem with most networking solutions is that they require specific firmware as well.
Even GHI is experiencing that. Thus the note: Currently, this module works only with FEZ Spider Main board.. It doesn't work with other gadgeteer mainboards.

Sounds like that.

Upside is that this is real WiFi not a Wifi-Serial bridge.

It's crazy, I bought an external WiFi-Ethernet Bridge with extra 4 ethernet ports and it has webpage for setup, antennas, WEP etc. for ~$50 so in practice it may be better to have an ethernet convertor and lose one SPI then use an external box like this. Only downside is that it takes more space...

So what's the best way to get Ethernet assuming direct socket to NGO is not available now and Shield is the way to go? I'm sure many have used a solution to make a Netduino Plus out of a Netdiuno and there is a rather standard answer for this now. Also correction: Looking close in MCU datasheet I see there are three SPIs: SPI1 can communicate at up to 37.5 Mbits/s, SPI2 and SPI3 can communicate at up to 21 Mbit/s. T Now I wonder if solution (1) above messes up with SPI1? If that's the case I lose the faster one

Wow, then it's a lot of problem. Another option I had in mind becomes more relevant now: 1) Getting the new Fez Cerbuino Bee: http://www.ghielectr...log/product/351 for $40 then it works out of the box with $35 Ethernet: http://www.ghielectr...log/product/333 according to the former link also it's easy to do WiFi (using WiFi-Serial bridge solution of XBee Socket which is already there plus Roving Networks RN-XV Module for $35: http://www.sparkfun.com/products/10822) So for total $75 I get fast MCU + Ethernet (or the same price for WiFi) ! It has USB/SD Card/Power Barrel/USB Host etc...

I had a program running on Netduino (Plus) and it was working for months. The device is turned on and off occasionally. After a while it stopped working. I guess the program got wiped out of memory or got corrupted somehow. I reloaded the program and the system is working now. I wonder if Netduino is not connected to power, doest the program over time get off the memory? 1) What kind of memory Netduino use to store memory? 2) Is it possible that this memory is wiped over time? 3) Is it possible that static electricity is the cause? 4) Is it possible that accidental tripping of reset make the memory go away? It's unlikely but I can imaging a static charge on reset ping of N+ (thought it's not connected to my main board) makes a reset. 5) I used to have out of memory as garbage collector couldn't keep up but that should not change the actual memory of program, right? This doesn't seem to be the cause since wiping/damage of the program is permanent. Thoughts?