The theory goes that originals are needed because there are so many problems with forgery. At market stalls in Tunisia, for example, you can buy a year's worth of HSBC bank statements for 6 quid.
In the fast-track countries they are less concerned about risk than elsewhere and you can get away with a lot more. But sadly, fraud in America is on the upswing and as a result 2008 year-to-date refusals at the NYC consulate are running neck and neck with Moscow. They were always close, within a percentage point, but it was never a dead heat.
So yes, they expect originals; but failure to provide them is not necessarily a showstopper for the fast-tracks. If you didn't submit originals, your strategy at this point would be to gather up all the originals you can (every. single. one.) and hold them in reserve for the 28 day local period. If it comes to that, and if you have everything, it should be a breeze.
Otherwise you'll be fine.