Just released this morning it would seem:
Looks like 100% flood!
Buy ! 
Now I would be extremely tempted if they have the neutral white version...
Very Nice!
Looks nice, smaller than H51, floodier, really neutral/CRI version would be nice.
Lets see, how many years, from now these acrually are available?
Like Q50…
me too waiting neutral one ...
Neutral version, H502W, available in June, according to the Zebralight comparison spreadsheet on their site. Good to wait, and let them iron out any teething problems.
Edit: Just noticed that HKequipment now have the 2xAA SD52-CW headlamp on sale at $69 (or $75 with magnet). Just a coincidence, I expect.
I was just about to post this was in stock (it was pre-order when I last checked) but did a search to check, looks like I’m about a month slow 
The H502 neutral has gone from “June” to “2012” release date. Waiting for the emitters, it seems. Ah well, better get something else in the meantime.