This is a lightweight gaming PC. It's built to be upgradable, mostly because of its low cost.
The first thing you should upgrade is the cpu
You could have gotten better performing components for now, but since you said you wanted the ability to upgrade, this isn't bad.
Maxwell is nvidia's next GPU. the codename you want is BROADWELL. Not a big issue unless you buy a GPU as a CPU. But you know the difference.
I may be misunderstanding you, but if you're planning on stick a Broadwell CPU in that mobo, you're going to be awfully disappointed. Although Broadwell is going to be on the LGA 1150 socket, it will be utilizing a different chipset than Haswell meaning it will require a new mobo anyways.
Although many would say to upgrade the CPU first, I'm going to say something I don't think I have before; get a new case first. I say this because yours seems to have absolutely no cable management options, and if you're going to put out the effort involved in building a PC, you might as well get a case with a window so you can show off your hard work.
You can upgrade to i5 or i7 Haswell CPUs not Broadwell. Anyway it's a decent budget build.