I don't hold out much hope for a good deal
For *years* people have been regularly posting to www.ideastorm.com, begging Dell to put Linux on their machines, but whenever Dell does it, it sets out to deliberately make the Linux purchasing experience hard and often more expensive:
* They don't Linux as an OS choice for any of the models that they sell with Windows - this would be the easiest way for Linux to get some sales, but Dell are too scared of MS (e.g. losing volume discounts) to do this.
* They put the Linux machine well out of the way of the normal model list. Instead of just being another model in the appropriate section, they put it as a well of out of the way link called something like "Open Source Desktops" or some such vague description.
* They don't do an identically spec'ed Linux machine to the equivalent that comes with Windows. The reason for this one is obvious - users will be able to deduct the price of one from the other and work out how much Windows costs to the end user.
* Because of the difference in specs, you'll often find worse specs on Linux machines despite the selling price being roughly the same as Windows machines.
* All the endless short-term offers (50 quid off, extra RAM, bigger hard drive etc. etc.) seem to only every apply to Windows machines and never to Linux ones.
It's now wonder that previous Dell attempts at selling machines with Linux have failed - they've deliberately designed to fail from day one. I hope that these XPS machines buck that trend, but I don't hold out much hope to be honest. Any bets that it'll be more cost effective to buy the Windows XPS 13 and dual boot it to Linux instead? All I'm asking is that the Linux version costs the same as the Windows (doesn't have to be cheaper, though that would be nice) one and has the same hardware spec too - is that too hard to ask?