goodroi - 7:02 pm on Oct 2, 2012 (gmt 0)
I assume your site has more than one page indexed in Google. Did you check to see what is happening to your other pages? If your other pages lost inbound traffic than your site has issues and its not just because of your homepage change. I suggest you look at referring keywords and landing pages to better understand how your site is performing.
Most websites are not crawled by Google in real time. If you are running a very popular news website then it might be the case but for most webmasters it is more likely Google is visiting their site on a daily basis (or less frequent) and then updating the index. So I would guess that your homepage did not cause your trouble. That being said, it does not mean your homepage changes are good. If possible you might want to think about undoing the changes just to simplify your search for what could be wrong with your site.