New high-end desktop processors, including the replacement for Core i7 4770K parts, are coming from the house of Haswell and they are called Haswell refresh, while Broadwell comes to desktops but in a different form. It turns out that Broadwell for desktop will replace Haswell 28W and 15W desktop parts, mostly targeting all-in-one systems as well as home entertainment living room PCs or nettops. It is still unclear whether we will see NUC products based on Broadwell.
The highest end Core i7 Haswell based to be replaced by Broadwell is the Core i7 4558U, a 2.8GHz clocked dual-core with 4MB cache that works up to 3.3GHz with Turbo. This processor has support for four threads and a maximum TDP of 28W. With Broadwell version the performance should rise and TDP might actually go down.
At some point in the second half of 2014 Broadwell comes to the 15W segment to replace 1.7GHz clocked dual core Core i7 4650U that has 4MB of cache and a max turbo frequency of 3.3Ghz. Even at 22nm Haswell core this CPU is maxing out at 15W and with Broadwell replacement things might get even better.
All 15W and 28W All-in-One Haswell parts will be replaced by Broadwell, with more than a dozen of SKUs. This is also confirmation that Broadwell doesn’t come as a traditional socketed CPU as these parts cannot be user-replaced. Core i7 4650 U uses FCBGA1168 which is not compatible with motherboards and LGA 1150 desktop boards and we suspect that Broadwell won't be either.
We are quite sure that Apple might be very interested in 28W and 15W Broadwell processors for its overpriced iMac series coming in the second part of 2014.
This basically means that the only way of getting a Broadwell desktop will be to buy an AIO, or alternatively small-form factor PCs and barebones based on mobile parts.