Looks like a nice processor, and I like that it is 5 V tolerant. The downside I see is the low pin count, connect a glcd to that thing and your almost out of pins (just an example). But the biggest downer for me is that it needs windows or emulated windows (no experimental Mono please). Do people actually still use Windows? 

I'd rather use my PI if I need Ethernet, and unlike Nick Gammon I've had no problem installing linux on it. Tho that might have something to do with that I've been using Linux now for the last 10 years or so.

Settings the fuses can be done in AVR Studio (with a GUI) so the change of you doing anything wrong is more or less non existing.

I set the baud to 1200 in terminal and:
1. Hyperterminal gave me "f"s every second, instead of the temperature (that was my sketch about);
2. serial monitor in Arduino IDE returned random characters (not squars this time, but random ASCII) every second.

So I guess it is not the clock?

If your 1 second delays is 8 seconds then it's the clock, no doubt. And the divide by 8 fuse is set by default so you have to change it.
Just to be sure, you have selected the "Arduino Pro or Pro Mini (3.3V, 8 MHz) w/ ATmega168" board when programming the atmega 168 right?

That is switching many pins on and off right? If so, have you tried switching just one pin?

Who has one with the RTC Crystal can tell me what on the surface so I can order me one by my self

I don't think there is a due that has the crystal. No one has reported that they have gotten one.

USART uses minimum 3 pins right? MISO, MOSI and SCK. Are the third pin there too?

The file available on the website is the latest available design file for the Arduino Due.
As far as I know this is the file used to generate the production files.
I will investigate further and update the file if necessary.

Consider that the factory will apply some minor tweaks to our reference design before going to productions (usually with their own CAM software) therefore some minor differences are possible.

A possible answer for b) is that the factory normally has two stages of manufacturing, a first batch where many steps are still sort of "handmade" to make sure the process is smooth then they move on to large scale manufacturing where they might introduce some more tweaks (usually to make it easier for them to do automated testing, optimising the pick and place machine programming )

The Y2 oscillator is in the schematics but is missing on the actual board. May I ask why you removed it? I hardly think that the manufacturer just left it out to make life easier for them :>.

I've never had any problems without caps or pull-up so I left them out.

In that case, I have tiger repelling rock to sell you.

Please send it so I can try it out first. I'm pretty sure that it will work great here in Finland, but you never know. Anyway, if I ever where to use that thing I will solder a pull-up on the back to make you happy, but not a cap! Living on the edge!   

btw, attached here is the icsp header I was asking about, no dot's on my board. All the other headers around have the dot, not this one.
but if the pinout in the first picture is correct, I guess the dot should be on top left corner of the header.

My Due got the dot, it's actiually on the bottom right.

[using analog? need 100nF cap on the Aref pin10K reset pullup resistordiode such as 1N4158 across the resistor (anode to reset pin, cathode to Vc]

What part of the Arduino functionality would you like to keep?
At a minimum you need:
the '328P
16 MHz crystral
two 22pF caps
100nF caps on VCC, AVCC pins
using analog? need 100nF cap on the Aref pin
10K reset pullup resistor
diode such as 1N4158 across the resistor (anode to reset pin, cathode to Vcc)

optional:
Header pins to connect FTDI Basic/FTDI cable, and 100nF cap to connect to Reset pin
or
header pins to connect to ICSP header for rebootloading or for installing bootloaderless sketches

place to connect 5V wallwart, or a battery, or a 5V regulator

Here's an example for a ATmega1284P type board, a '328P would use a smaller connector
This one has both FTDI and ICSP headers, but does not have the diode.
It has screw terminal for bring in 5V power from a wallwart or 4.5V from a triple-AA battery pack (I've used both)

why do we need to pull up resistor when we need to use analog ?and also the cap.

ATtiny2313 doesn't have analog input :>

I've never had any problems without caps or pull-up so I left them out.

That's like saying "I never had an accident in my car so why does it need an airbag?"

It doesn't matter of you have an airbag or not if your just standing still flashing with out headlights.

There is no need for any external components, and no attiny/atmega dosen't even need a crystal. They (atleast all I've used) have an 8MHz internal crystal. All you need is voltage and ground.

Well, you really should have a bypass capacitor on VCC / GND and a pull-up on RESET.

It's recommended, yes. But as I said I was bored and wanted to make a minimal board (I'm not using it for anything). I've never had any problems without caps or pull-up so I left them out.

Very nice. Don't you need to customize the boards.txt of the Arduino IDE for using the internal 8MHz ? I thought that meant using specific "fuse settings".

I don't use the arduino IDE. But no, the attiny is not supported. If you want to use the IDE without any custom editing you could do the same board with an atmega168 and program it using "Arduino Pro or Pro Mini (3.3v, 8 MHz) w/ ATmega168".

It's not possible to program the due with the maple-ide as they use another processor. Getting the pwm feature from the maple-ide is possible, but it would probably be less work the rewrite the arduino-ide analogWrite command and add a set_pwm_freq command.
So as I see it you can either..
1. use the maple.
2. write your own function that sets the freq of the pwm as well as the duty value.
3. wait till the arduino guys has done something about it.

I've seen on your blog that you are designing a shield for it, one alternative would be to make the shield for the due and just use wires to connect the maple for now.

I'm not a windows user but you could try another unpacker. 7zip is a great small app that can unpack almost everything.
http://www.7-zip.org/