New opportunities come up throughout the year as different grant awarding bodies release funding decisions at different times. Keep an eye on the New Projects section of this site. Whilst more than half the studentships for October 2004 (including ones which are yet to be announced) are probably already filled (or have closed applications), there's still a lot around. Competition is stronger at this point, because as the year progresses more people tend to make the decision to try for a PhD.
You should keep applying now though, as the longer you leave going back into your subject, the harder it will be to find a place.