I finished C25K a month ago and since then I haven't really been actively trying to run faster, I've just been following the advice that increasing distance will lead to a better pace. I have probably upped my distance a little too steeply (I'm going to tone it back a bit over the next few weeks) and last week I ran 16.5 miles which shows that not only am I fitter than I was a month ago, but that I am also getting addicted to running!
My previous best for a 5k was 30:35 (9:50 pace) but today I managed to run one in 28:42 (9:14 pace) which is a massive improvement for me and shows that I am slowly but surely getting better. For my longer runs I am running slowly (yesterday I ran 5 miles at a 10:54 pace) and it obviously isn't hurting my shorter distance pace. Going to keep doing more of the same and hopefully in a few weeks I'll be running even faster.