At some point in the last few days, the new Iris Pro versions of the Skylake chips were formally announced. There's no formal street date yet, and I've seen estimates ranging from a couple weeks to a couple months.
The i5-6350HQ and i7-6770/6870HQ will be the ones of most interest to this crowd (it's unlikely many machines will offer a choice of which of the two i7 models you can get, although the slightly larger cache on the 6870 is preferable if you do get the choice); the i5-6350HQ if it follows the Intel SRP looks like a heck of a deal.
The advantages of these are two-fold:
First, if you need GPU power -- or think you might later -- unless you need a really big GPU, this is a big win. The GPU performance is about 3x what it is with the regular Intel integrated GPUs, and looks likely to be much better than low-end gaming/professional laptop graphics, and at least comparable to the last generation midrange chips. At the same time, it doesn't require the board space and separate cooling, or higher power use, of a discrete GPU. Plus in many cases the ~$50 price increase of the better iGPU is going to be no higher than a low-end or midrange dGPU.
Second, if you don't need GPU power at all, these chips have a 128MB eDRAM cache. It's mainly there to speed up the GPU, but it absolutely shows a measurable performance improvement on memory bound benchmarks. This is likely to be especially helpful for software developers and people running VMs (and to help a lot more than the loss of the smaller cache on the i5-63x0 and i7-67x0, where I'd usually be saying the extra 2MB of cache on the i7-68x0 was worth the potentially fairly large cost bump.)
Oh, and for Linux users (I realize this is very niche) the Linux support for Intel graphics is on a whole different and better level than the Linux support for NVidia switchable. (I haven't used AMD in such a long time that I can't comment.)
I was on the fence about how soon to order my new machine, but at this point I'm going to wait to see what my options with one of these are.