I don't suppose they've considered making IEEE 754-2008 decimal floating point numbers the default number representation. It's a shame Intel didn't consult Dr. William Kahan earlier in their design of the x87 floating point unit. At this point, binary floating point is deeply entrenched despite most uses outside of scientific modeling being better suited to decimal floating point. Most spreadsheet calculations are be…
There's also DEC64, Douglas Crockford's proposal for a decimal floating point type to serve as the only numeric type in future programming languages: http://dec64.org/
It seems the main claimed advantage of dec64 over IEEE 754-2008 decimal64 is in the fast-path zero-exponent case. Note that V8, SpiderMonkey, and many other dynamic language implementations use a separate compact fast-path representation of integers that renders this point moot. Also, no benchmarks are provided to show the supposed speed advantages of dec64 libraries over decimal64 libraries.
Also, I doubt the dec64.org's claim that the primary reason for slow uptake of decimal64 is the speed of software implementations.
In short, dec64 is mildly interesting, but its claimed advantages aren't enough to justify abandoning the decimal64 format that already has hardware support and language support in a very popular language. Intel also had a large role in standardizing the decimal64 format, so I suspect they'd be much more likely to implement decimal64 in hardware instead of dec64 in hardware.
Edit: on a side note, it's unfortunate that neither dec64 nor decimal64 forces normalization, complicating comparison and sorting.