I think it'd be best to only put this if clause around the script tag creation part below. I know you don't have any code that relies on GA existing yet, but you could more easily add some in-page tracking if you knew `_gaq` would definitely exist. 

Another thing I know some like is to split the snippet and put the array creation in the head, and the rest at the bottom to make the page a bit faster. 

https://developers.google.com/analytics/devguides/collection/gajs/#SplitSnippet

Totally up to you. If you know you're not going to do fancy things you can leave it.