Intel CEO Brian Krzanich confirmed with Reuters this weekend that for Broadwell CPUs shipping he can "guarantee for holiday, and not at the last second of holiday." We've known for a while that Broadwell was delayed to H2'2014 and from the look of things now the processors will probably roll out around October to allow for ample time to appear in new PCs for Christmas sales.
Broadwell is the successor to Haswell and will feature improved integrated graphics, new instruction set extensions for ADX and RDSEED and PREFETCHW, VP8 video decoding support, and numerous other enhancements. At least to fill the time until the Broadwell processors make their debut is the Haswell Refresh launch that's happening soon. On the Linux side, the support appears to be in pretty good shape for Broadwell with the CPU and graphics performance while a few extra months will hopefully allow for some better optimizations and tweaks.