It seems my initial response hasn't gone through moderation so I can't edit it just yet; I wanted to point out, though, that I did manage to reproduce the problem on yesterday's nightly after I'd set the value to a real number as mentioned.
After testing it a bit, it seems that LiteralNull also shows an empty "=" sign, but I don't know if that's intended?
Yes, that's the same issue as I have, and yes I'm a SysML guy. I use 0.10.2.v201403040623 due to some other issues I had that were mitigated in that build. I can update to the latest 0.10.2 nightly, unless you have tested with a Luna nightly? Then perhaps this issue remains in the 0.10.2 builds?