I realize that a computer upgrade is very tempting, especially at such low prices, however, aside from usb 3 or the current gen fx-xxxx AMD processor you honestly don't have any reason to upgrade your motherboard.
There's also no such thing as "future-proof'ing" your computer. Given the fact that computer parts are getting replaced / refreshed every 6-12 months, last-gen parts will be cheap and next-gen parts will be faster and more power efficient, generally speaking. So even if you buy, lets say, a phenom II x6, in a couple of months be sure that there will be something better in all respects (including price) and by the time it does you'll realize you haven't used half of this new cpu and if you kept your older one you wouldn't know the difference.
Given your computing needs, a new cpu, gpu and not to mention motherboard will hardly be noticable. A new SSD, however, will definitely make your computer noticeably faster.
My advice to you is basically to upgrade when you need it, and not when you see a shiny new product at a bargain.
It's just me though.