Sources: AMD , 
quote: They could throw in as much CU as in the PS4 and may be an extra steamroller module or two.
quote: Over the next 2 quarters, the 14nm FinFET and 20nm planar process technologies should tape out.
quote: After a back and forth debate rumor-wise about whether it was feasible to pool GDDR5 and DDR3, the believers won out as AMD has indeed adopted this novel technology for Kaveri. The 28 nm chip features a new "HUMA" (Heterogeneous Unified Memory Access) as outlined in slides which leaked in April 2013.
quote: ... of course it's somewhat unclear whether AMD is talking about the Iris/Iris Pro Haswell chips or (more likely) the HD 4600.