It depends what you mean by Zeitgeist. If it really has a main theme that's going to be past its sell-by date by 2014 then you should work day and night to do the best edit you can and send it off - if you really, really believe in it.
If it's just details of technology etc. then you can afford to wait until you can devote time to doing a really thorough edit.
Any book that's taken on by an agent next week isn't likely to see the light of day until 2014.
You should always submit a completely polished manuscript and it should already be edited well and really the finished deal. Agents have huge submission piles and any spelling errors etc will instantly direct you to the slush pile.
I would suggest putting it aside for a while - then going back and doing a really tough edit. Only then should you send it.
These days agents are not looking for potential - they are really looking for the polished article.
I have a question and was hoping you'd have some advice - at what point in the editing process would you submit your book to an agent or publisher? I have written the book, and done one edit. I have had someone else read it, and am now working on my second edit, so third draft. Problem is, I am now very busy with work etc and just don't see myself doing a fourth round this year. Also, my book is very zeitgeist, so already in my edits I am having to make a lot of changes as times change, especially on parts of the novel I wrote in 2008 - small things, like turning the character's flip phone into an i-phone, or songs that are on the radio. So I am not sure - start sending the book to agents after this edit anyway, or wait until I'll be able to find time to do more work on it? I feel like I have lost all perspective about whether it is good or not.