I think its just the arabic word "Emirates". It appears on the fuselage in normal script I think, alongside the larger, English language billboard version.
I may be wrong, but I think the "symbol" that appears on the engine nacelles and also on all marketing material, hats, uniforms and printed matter is just the same word in Arabic - i.e. "Emirates", but written in a "nested" configuration on two split levels, as apposed to the continuous form on the aircraft fuselage.
In English translation, what I mean is:
E M I R A T E S
(fuselage)
E M I R
A T E S
(engines, hats and literature etc.)
I know the above looks daft the way I've written it, but its the only way to explain what I mean.
The tail colours are clearly a stylised representation of a wavy national flag.