While I normally promote laptop gaming, in this case I have to agree with others.
My suggestions for a gaming laptop that could _possibly_ run Witcher 3 comfortably would have definitely been well over 1000€ (closer to 1500€), and even that would have been just guessing as we don't know yet how demanding W3 will be, and how well it will scale to slower PCs (including laptops). And anyways, buying PC hardware in advance for some future game is not a good idea overall (unless you really have to have the PC now). The longer you can wait, the more power you can get for the same buck.
That said, I was actually amazed how well I got e.g. Witcher 2 to run on one HP laptop last summer, which cost around 800€ if I recall correctly. Sure I had to lower lots of graphics options and run it in a lower resolutions, but even then it looked quite good and ran pretty nicely overall. I was expecting it to either be a slideshow on any settings, or even refuse to work at all.
So depending how well Witcher 3 will scale, maybe it will run pretty nicely even on a bit older and slower hardware. Highest end PCs are needed for the higher graphical options.
If one wanted to buy a laptop for running Witcher 3, or any higher end games, I guess you should look into something with NVidia Geforce GTX 880M graphics, for example ASUS 750JZ (much more expensive than $800 now, e.g. here in Finland it costs 1499€). Not sure if it will be enough to run W3 on the highest settings, but otherwise I expect it to be fully playable and looking great on it. I guess.
Oh yeah, and getting one with Windows 7 preloaded is getting harder and harder. I don't think e.g. ASUS ships any of their newer laptops with Windows 7 anymore, so you'd have to buy Win7 separately somewhere (more costly).
In my opinion backwards compatibility is not a major concern with Windows 8, compared to Windows 7. There are even some games which have (more) problems in Windows 7 than in Windows 8. I recall there is even at least one GOG game which is supported with XP, Vista and Windows 8... but not Windows 7, as there are some issues with it.
Post edited June 14, 2014 by timppu