Their stated reason for de-prioritizing 64-bit builds wasn't technical; rather they say they don't have the manpower to do both. Perhaps the manpower issue is

Their stated reason for de-prioritizing 64-bit builds wasn't technical; rather they say they don't have the manpower to do both. Perhaps the manpower issue is that they don't have enough people to work on the JIT issues on x64 and do everything else, but I do not believe they specified.