1) Make sure whatever board you have will support the new CPU (chipset, overclockability, I/O)
2) Make sure that you will not use all of the PCI-e lanes on the CPU (do you have SLI? RAID?)
3) Make sure that your cooler is sufficient for the new CPU, and that it will fit onto it.
4) Make sure that it is a necessary upgrade for your workload. Do you need all the cores, cache, and threads?