Seeing as I also have a 09 SE like the original poster, and I'm also in the habit of standing on the pegs (not at 70 mph like him though...
) when travelling over humps or rough ground, I got a bit worried.
I've had a look at the footpegs fixings and, although they're not the world's finest, I can't see how a shear load sufficiently strong to break the stud can be applied.
The peg is held to the frame with an M8 stud and self-locking nut. The stud is welded by 3 spot welds to the U bracket. Shear loads should be taken care of by the two stamped 5mm dowels and the friction created by the tight stud on the two contact surfaces (0.81 sq Inch in area). The stud should be free from these shear forces unless the nut is loose and the stud threads have to bear the brunt of the riders weight.
Before this happens the rider with a bit of sensibility would notice the wobbly footpeg I would have thought, but you never know.
I'm including a couple of photos to encourage others to give us their opinions on this. They're for the passenger pegs, but the fixing method is the same.