Why not buy your ideal motherboard and build your sysytem. Then when you see the chipset and CPU socket being replaced and sidelined......this is when you can buy a backup motherboard (cheap) to replace and extend life.
Funny how buying a replacement motherboard can be torture and its overpriced........ But not so for a replacement CPU. Ebay is full of used reliable CPUs. CPUs don't fail but motherboards do. Years ago I cooked a few CPUs but it did not harm them.
The trick is getting the CPU-compatible backup motherboard before stocks are depleted and prices rise. This is already the case with the MSI A88X-G45 motherboard.
http://www.amazon.com/gp/offer-listing/B00IC5XZ98/ref=dp_olp_0?ie=UTF8&condition=all
It sold out of most places within a week of the news coming out about future AMD chipsets being MS-only compatible. Those who had some left jacked up the price. Seems lots of people had the idea of upgrading while they could.
I may have to go with one of those Used boards. That’s what my current overpriced Sabertooth is -a Used board which cost $100 more than a new one when they were out.