The Intel Microcode Update Guidance presents an update for Spectre and Meltdown fixes, at least when it comes to a good number of 4th gen Haswell and 5th gen Broadwell platforms.
The updates address Variant 2 of the three Meltdown and Spectre CPU flaws, and should be available for all Haswell and Broadwell chip families except the Broadwell Server EX and Haswell Server EX, which remain in beta. The stable updates are available for Xeon and Intel Core i chips, including Broadwell H 43e-series Core i chips and Broadwell U- and Y-series Core i processors.
As for Sandy Bridge and Ivy Bridge updates, these remain in beta-- meaning they are released for validation under non-disclosure agreement. Intel also says there will be patches for processors and platforms dating as far back as Wolfdale, the 2007 Conroe die shrink.
PC makers should be releasing the Haswell and Broadwell updates as firmware or BIOS patches.
