Okay I joined.
If setsubo bunny were still a member here, she'd kill me.
However, my "logic" behind Lelouch being "alive" is probably a bit different than some peoples.
It is my humble opinion that Okouchi intended for Lelouch to die at the end of Code Geass, but that Sunrise (in their infinite wisdom) insisted on a vague ending (the cart-driver sequence at the very end) just in case they wanted to make a sequel with Lelouch in it.
Therefore, Lelouch lives in a sense.