Hmm...

Well, showing the gym battles and contests from the beginning of the series IS a good idea. It's been 3 years since Houen started(IIRC), so having a refresher like this is good. Clips show may not be useful in the "oh look they advanced the plot or at least gave us something new" sense, but they ARE useful in the "my memory of that was foggy but this episode helped me remember that" sense; although Pokemon is less confusing to try and remember everything that happened than, say, Gundam SEED Destiny, it's still nice to get a recap on what happened.