There is a reason why "we coders" got away from line numbers, they change often. If someone gives us large chunks of code they don't understand, presenting line numbers is going to encourage them to continue to think in large chunks ... line numbers are not going encourage Seekers to clean their rooms.

My opinion is that this is just adding more features that some us don't even want. Why complicate things when it just enables bad habits to persist?

UPDATE:
"Well, your own blog displays code with line numbers."

Yes. And i didn't really like it. What a weak argument. A strong argument would be how Github uses them. But when it comes to merging code, the VCS needs that information. Again, it's information that is better suited for computers (robots) than humans. Petty arguments aside, The bottom line is i would prefer for such to not be a default here.

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)