If you find out in book 12, dont tell me!

 

but if you dont... anyone know what the crown means?

As of this point, Logain has not yet fulfilled Min's Viewing(s) relating to him and "glory to come."

I figure it has to have something to do with the Ashaman.  Just speculation though.  Nothing confirmed. :)

He will be the one to pull Callendor from Rand's Heart after he sheaths the sword,

or from the Dark One's Heart after Rand stabs him. (Hopefully the Dark One will survive)

 

and Logain will become the one who follows after.

 

 

*just my opinion in case some idiot starts asking for my sources; which happens far too often.

It's the crown of Murandy! ;D