Checking http://www.coreboot.org/Supported_Motherboards, there are several Intel Reference/Evaluation boards that are supported.
If your Intel board is not listed, look up the chipsets used on the Intel web site and check http://www.coreboot.org/Supported_Chipsets_and_Devices to see whether each chipset is supported. If all chipsets are supported by coreboot, it should be relatively easy to create a configuration that builds a coreboot firmware image for your Intel board. Any board specific features may not be supported, but all major features of the board should work fine.
I have no doubt that Intel is working hard to support the software that its customers want and I'm quite sure that includes coreboot. coreboot is exacly what embedded developers need to support Linux in embedded designs where cost is a critical factor and commerical BIOS software is often too expensive. Once coreboot supports the embedded version of a chipset, it should be rather trivial to extend that support to non-embedded versions of these chipsets and thus we could have coreboot support for Intel mainboards for non-embedded (Desktop, Server, Cluster, etc.) as well as embedded markets.