We've heard Intel talking about plans for software upgradeable CPUs before, but now it appears that they're going to be putting that plan into action with a trio of their Sandy Bridge parts.
Intel indicates that upgrading the two desktop CPUs will give users a clock speed boost, while the notebook chip gets a higher clock speed and additional cache. There are no specifics on the magnitude of those changes, though. Instead of revealing the specifications of the upgraded CPUs, Intel has instead released a series of benchmark results illustrating performance gains across multiple benchmarks and applications. The numbers show performance improving by 10-23%, so we're talking about more than just a few MHz.
The cost of each upgrade hasn't been released, but the FAQ includes a few notable details. Windows 7 is the only operating system that's supported, and only "select" systems will be allowed to participate. It looks like the upgrades will be tied to a system's motherboard, too. The FAQ mentions that upgrades will have to be reactivated if there's a mobo swap.
The Tech Report has the news.