BFL is predicting their 28nm chips will use barely less W/GH than BitFury's 55nm chips, when they should be at least 3x better than BitFury, if their design was as good. BitFury's 28nm chips (if they plan to do that) ought to be awesome.
Without getting into BFL's 28nm plans, it's boggling how their 65nm design is eating 4w/GH even after their epic development time, whereas this 55nm design is well under 1w/GH and seems to have come out of no where.
BitFury's design didn't come out of nowhere. His FPGA design(from what I've read) was superior to any other design on the market. Reading the little information that was fed to us, BitFury's 65nm shrunk 55nm chips were designed to be a low-voltage and efficient design. They missed their hashing/chip goals but the design has been proven to display fantastic efficiency and power-consumption/throughput scaling.
A 28nm poorly designed chip could easily be worse than a well designed 55nm chip. I am excited for all of these upcoming 28nm chips but I'm really excited to see what comes out of BitFury(28nm die shrink perhaps?) and CoinTerra(due to the credentials of the team). I think this next generation of chips will be the generation that we mine on for a year+ as great designs will be limited by the manufacturing process, unlike the past where 110-180nm designs had a lot of room to scale with optical shrinks.