So this pad would work well for ski mountaineering and ski touring?
Does cold camping mean it will keep you warm in the winter?
To what temperature is it good to?

The ProLite Plus or a closed-cell foam pad would work much better for winter camping. The NeoAir only has an R-Value of 2.5 whereas the ProLite Plus is 3.8, an important factor when camping on cold ground or snow.

Chad, I believe it has an emergency blanket-type sheet inside which is supposed to reflect the heat of your body back on to you.

I have a similar Big Agnes insulated air core. I've slept on snow with it before, and it was pretty chilly. However, if you throw a closed cell foam mattress on top of it, or an insulated thermarest, you'll be extremely comfortable and warm. My winter pack always gets a little bigger/heavier because of this.

It all depends on your metabolism. If you're a warm sleeper, this could work as a winter pad, however, I would caution you against it. I personally have slept on a Prolite 3 in winter without issue, although I was a little chilly (acceptable to me due to the size and weight of the pad). The NeoAir will be similar. A better option would be a NeoAir and a Z-Lite in combination. Both would weigh less than a standard pad, and having two insulative barriers will increase the R-Value. As well, the Z-Lite can't puncture so even if the NeoAir does, you will still be left with some insulation. Having the two will give you about a 5 R-Value. This would work for me in most conditions.

This is a very individual question. I would recommend checking out some of the gear forums at Backpacking Light. There's a huge amount of chatter over this pad. The consensus seems to be coming down towards 3-season use, but what works for one may not for another; we're all snowflakes, etc. I will be buying a Neoair for myself, but it won't replace my Exped Downmat for winter trips.

Whenever I go camping in winter I take my prolite 4 sleeping pad, which has an r-value (insulating/warmth value) of 3.8 I believe. According to thermarest this pad has an r-value of 2.5, so just a little bit less, but amazing for having no internal insulation at all. I have used my pad on the snow itself, in temps down to 0, with no cold spots at all. I would guess this pad would work quite well in winter all well...