As a general rule, I would think that high definition camcorders perform less well in low light than standard definition camcorders. The reason is that being higher definition means that they have more pixels, which means that those pixels are smaller, which means that each pixel has less light hitting it. Presumably, there would be a low light level that would still produce acceptable results on an SD camcorder that would look horribly noisy on an HD camcorder.
There are things that can counter that. A high definition camcorder with a larger sensor or more sensors might perform better than a standard definition camcorder with smaller/fewer sensors. An HD camcorder with a brighter lens (larger aperture or lens opening) might also perform better than an SD camcorder with a smaller lens.
All this assumes that you meant "high definition" when you said HD. If you meant "hard disk", that's another story. The optical processing on a hard disk camcorder is not inherently different than that of a tape-based camcorder. The hard disk camcorder will very likely use MPEG2 (possibly MPEG4) compression, which is typically more aggressive than DV. Because of that, the image quality might be slightly worse in low light - all else being equal.