It won't be that simple. Skip.dat has some sort of checksum or value relating to the contents of your wiiking2.sav. I'm not entirely sure how they relate, but you can't just take a blank file with skip.dat and have it work. You'd have to have a copy of this data and create a proper checksum or CRC, or whatever the game uses, for it to see it as a legit file. Otherwise it'll just complain that it's corrupted.
On the other hand though, I found an ocarina code on
http://geckocodes.org/?c=SOUE01 which will let us create Hero Saves right off the bat, except it'll have the first cutscene's playtime added on(since you wouldn't be able to skip, right? I'll try that too).. I'll try it out.
Edit: You can't skip the opening cutscene with the code, since it's a fresh save.
Edit2: Interesting..you can't skip -any- cutscenes with the code, since it's fresh..
skip.dat has CRC32 just like wiiking2.sav
skip.dat follows this basic structure:
struct SkipData
{
char data[0x20];
int checksum;
};
struct
{
SkipData skipData[3];
}file;
It's pretty basic and i'm still researching the data.
https://code.google.com/p/skyward-sword-save-editor/source/browse/trunk/save%20editor/SkipData.txtEDIT:
Also my editor Wiiking2 Editor has full data.bin support should you wish to edit your file straight from the data management menu.
The only caveat is: you need your Consoles keys and mac address, if you have HBC installed it's pretty simple to get them, there are various ways to go about it, but i'm not going to elaborate here.