I don't know why people get so attached to their motherboards. Unless you buy an enthusiast board that costs well over $300, they're worth replacing as they get older, even if they are compatible with newer CPUs.
Regardless of whether your motherboard will or will not be compatible with CPUs being released 3, 4 or even more years down the line, doesn't it occur to everyone that there will be new data transfer standards, interfaces, etc. making the prospect of keeping a motherboard for 5-10 years or whatever ridiculous number far from optimal as new standards are introduced?
If you bought a new motherboard even within the past year, you'll have good reason to replace it within the next couple years if it isn't USB 3.0 (yes, you can buy a USB 3.0 add on card) and SATA 3.0 compatible (SOL if you want to use new 6.0Gb/s storage devices) once devices using those standards become common and eventually the new standard.
Unless you update CPUs every 12-24 months or less, you're not going to get 2-3 update cycles out of your old motherboard unless you're okay with using dated storage device standards.
There's also the issue of memory speed compatibility if you upgrade to a newer processor with clocks that can take advantage of higher speed memory as it becomes available. Compatibility speeds are motherboard dependent which can be an issue if you keep it long enough.







