Worst buy of the century if you go for the Xeon, IMHO. The Core i5 is half again as fast.
CPU Benchmark for the Xeon is 4746: http://www.cpubenchmark.net/cpu.php?cpu ... 40+2.40GHz
CPU Benchmark for the Core i5-4570 is 7138: http://www.cpubenchmark.net/cpu.php?cpu ... 40+3.20GHz
And indeed the Core i5-4570 has integrated graphics, meaning you don't have to splash money on a discrete graphics card (and this being a Haswell processor, it beats out cheap discrete graphics cards with its performance).
I have the Core i5-2500k, a previous generation, which scores below the Core i5 you are considering (http://www.cpubenchmark.net/cpu.php?cpu ... 40+3.30GHz
). It can do all the CPU lightweight tasks you have noted at the same time with ease, as all those tasks you noted primarily need a lot of memory and a fast disk while barely using your CPU... These are all the kind of lightweight tasks that most of the time are waiting for you to do something, meaning the CPU is sitting there twiddling its thumbs
On an average day, I'll have a few terminals and editors open, run a few virtual machines (though often running up to a dozen), have music playing, have a web browser open with many tabs, probably some LibreOffice tasks, and so on. It all runs fine at the same time, and is barely using my CPU.
So go for the Core i5! Though because this is Haswell, and a very new processor, make sure you are running the latest kernel as you'll want to get the latest drivers from Intel (which are included in your kernel). So probably pick Linux Mint 15, and in Update Manager enable level 4 and 5 updates so that you get the latest kernel.
A side note; heavy multitasking means you will be using lots of memory and frequent disk access. You already have the SSD for fast disk access, but how much RAM are you intending to install? I considered buying 8 GiB RAM but spent fifty or so bucks more to get 16 GiB RAM instead. Most days I would get by on 8 GiB RAM, especially if I wouldn't need to run so many virtual machines, but I'm very happy that I got the 16 GiB RAM. 12 GiB RAM would have sufficed, but that wasn't an option.