No, to your question.
Leaving a child with other parent for couple of weeks is no biggie per se, but to put a "boys holiday" first and expect the missus to do all the work of looking after the nipper is a bit selfish, as it seems that isn't a "regular" situation (e.g. away for work a lot) from the way you ask... IMHO though.
As suggested, talk to your wife; how about 2012 LeJog with them as well, providing "support" and seeing you each day? You could then have time to get fitter, do LeJog in a shorter time as fitter and lighter load etc and have some holiday time with them, too?
TBH, the fact that you asked and used an "embarrased" smilie tells the story already...