Unfinished/untuned simcraft. I did a few runs with yesterdays nightly build and the built in T19 profiles in patchwork style. Just by changing some of the talents to the ones I currently use at live, frost dps bumped to 213k. When I look into this sheet and see max. values for frost peaking at 205k...
Also I had a look at Warcraft Logs BETA. There are not much frost DKs running around, but I found a very interesting log: tinyurl.com/h7duoc4
It's a bit older, so razorize fix is missing, but according to this forum this simply should not be possible.