Intel is pushing the preliminary hardware support into Linux 3.13 and hopes to stabilise it and push additional features for Linux 3.14. The big idea is that Broadwell support in Linux 3.13, should be as good as Haswell. This means that Fedora 21 and Ubuntu 14.04 LTS -- and other H1'2014 Linux distributions should be able to support the next-generation Intel hardware.
Intel is doing better than AMD at getting its chips into the Open Source arena. Stable open-source support only arrived post-launch for major new GPU introductions. Chipzilla has done better than Nvidia too where the open-source support is still largely left up to the reverse-engineering Nouveau community.
Over the weekend 62 patches to the Linux kernel were sent for enabling Broadwell support by Intel's Direct Rendering Manager driver. Intel is expected to release the libdrm and intel-gpu-tools support in the coming days. Stage two will involve the i965 Mesa DRI driver changes plus the xf86-video-intel DDX driver for X.Org support.