According to Jamey Newberg, White has been released to make room for one of the two pendng 40-man additions, Eddie Guarado and Kazuo Fukumori. One more spot still as to be cleared for the other.
Just to reset, the guys who are probably considered possibilities to be removed include Nelson Cruz, Jason Botts, Chris Shelton, and Scott Feldman. With the obvious selection of White for the first spot, losing just about any of these guys could come back to bite you, but I think my choice at this point would be Cruz. Shelton should be an asset this season, and I still hold out more hope that Botts comes around offensively than I do Cruz, despite his very solid winter.
A name that probably isn't much of a consideration, but that I don't think is likely to burn you too badly is Travis Metcalf. If things get even tighter, say, in spring training, he's someone I'd consider exposing if I had to.