Are there any benefits to omitting the closing body and html tags?
Why is the google.com homepage missing the closing body and html tags?
edit - wit
You're thinking of that as a standalone thing. If they've done several different things that save bandwidth then it all adds up. Each one might not be significant on it's own but if they have 5 or 10 optimisations then it's significant in total.
Also, those ten bytes may well reduce the data size enough to make it take one less TCP/IP packet which will have significantly higher savings that simply reducing the size of one.