I found out from Kano, who has updated her site for the first time in a while, that the theme song for Kiddy Grade 2 (the pilot DVD at least) will be sung by Minori Chihara (Yuki Nagato's seiyuu) as announced on her blog.
From what I can gather, the song will be Snow White Sanctary (純白サンクチュアリィ Junpaku Sankuchuarii), the single for which will be released on the 24th (CD Japan have already sold out of the first press, a slipcover, and Yesasia are yet to list it as far as I can see)
[update=20070129]Had a email from Yesasia to say they it is available there now[/update]
For whather ever reason, Yesasia have her listed as Chibara Minori (http://global.yesasia.com/en/artIdxDept.aspx/code-j/section-music/aid-814266/), but still don't seem to have that paraticular single.