We've requested the ability to save sort orders in a future version of Expression Media, but for now, that's not a functionality we have. However, there is a relatively easy workaround that will allow you to get back to a search or sort order quickly and easily:
Now, any time you want to get back to the same view, just click the option button next to your keyword. A word of warning, though: if you reorder the images without deslecting the option button, they become a part of that view. Make sure that you clear the option button before moving images around.