Can 30p cut in half for HDR be returned?

[mSpider]

I've got a sequence shot at 30 frames per second--with ML HDR.
I separated the light and dark frames so that I could use SNS-HDR to combine them (with very natural results).
Now I have half the number of frames of the same length of time.
What in your opinion is the best way to restore natural motion in After Effects?
...
I know that shooting in 60p would do the trick--but I don't like the look of 720p on the Canons...

[3pointedit]

Twixtor pluggin? You need to do motion estimation to interpolate the missing frames. Best result would be put this step first if there is movement within frame (process both streams). So that there would not be any ghosting (of moving objects) when you overlay images.