Exactly. Take the $249 for example yet again. There's a PCI-e 2.0 x16 slot, but since the CPU slot is a full generation of hardware behind, you'd end up with a really good GPU with a CPU that can't keep up with it. You need a mobo with sockets ready for the stuff out
right now, not a mix of now and before, or just before.
Let me put it like this: A motherboard is the base piece of hardware that everything else connects to. There are many, many sockets, but the ones you should be most concerned about are the Processor (CPU), Graphics (GPU) and RAM, as those are the ones that vary the most and are the most essential to performance.
Over the years, new sockets for new CPUs and GPUs have been developed, like the 478 CPU or the AGP GPU sockets (both of which are fossils now). We've developed much more advanced hardware and have thus also improved the sockets. You want the current sockets so you can "plug in" the good stuff.
The last hardware gen saw prevalent use of the 775 CPU socket, which was for your Core 2 Duo and such. Now, however, we have the i-series, which only works on 1155/6 or 1366 socket types.
The 1155 seems to be a sort of "special" case , as it's designed almost solely for the Sandy Bridge model Intel chips (I'm not entirely sure, so correct me if I'm wrong), but those are
extremely good for gaming. And it just so happens that the computer I linked comes with the 1155.
Also, I apologize for the liberal use of the Edit button, so be sure to read this all again in a few minutes or so.
