paulr02 :
I'm looking at upgrading my 3 year old gaming PC and I realised I have a Gigabyte motherboard with an AM3+ socket, so my question is, should I look at buying a new CPU and motherboard in the very near future?
AMD's Socket AM3+ is as "dead" as Intel's Socket LGA 1150 (the socket that Haswell processors use): that is, there aren't going to be any new CPUs to replace the current crop that runs on those boards, but they still have some mileage in them (& anyone that thinks "5-year-old CPUS" don't have gaming life in them hasn't been paying attention to how 5-year-old Sandy Bridge chips have been performing).
As to whether you need to start from scratch or can upgrade what you have...it depends...
1. Is your current system having issues? This is the #1,
[most important consideration. And no, I'm not talking about, "well, my system is getting a bit old, so I think it's time to replace it", I'm talking about, "OMG, I just bought a game that came out a year ago, & my system's performance is so craptacular I might as well be using an old AMD Thunderbird system". Note that I'm not talking about random glitches or crashes, I'm talking about not having enough horsepower to run new games as well as you'd like.
2. Have you checked to see if there are any upgrades available for your platform? For example, not all AM3+ systems are created equal: a very old system running an FX-4120 with 4GB of RAM on a 5400RPM hard drive, for example, is going to sputter along compared to an overclocked FX-8370 with 16GB of RAM & the OS on an SSD. Same with a system running, for example, an old Radeon HD 5450 compared to one running an RX 480 or GTX 1060 (let alone a top-line GTX 1070 or 1080). If you can spend just a little bit of cash to improve your current build, it's a lot more cost-effective than chucking everything out the window.
3. Do you have a particular budget in mind? If you can only afford a few hundred dollars, then you won't be able to replace your system with any kind of "good" replacement (unless you're willing to settle for a Core i3 on a mATX board). OTOH, if you have $1,000US or so floating around, you might be at a prime time to switch to a Skylake build...although I would only recommend that if a) your system is at the end of its performance growth (including any upgrade possibilities), & b) you can't wait until Zen has been released & benchmarked.