Subversion or restoration?

Byron Borger waxes enthusiastic over Brian Walsh and Sylvia Keesmaat's new book, Colossians Remixed: Subverting the Empire, just out from InterVarsity Press. In the course of his review, Borger alludes to Walsh's Subversive Christianity: Imaging God in a Dangerous Time. Having worked with IVP, I know that an author's preferred title is not necessarily the one that makes it to the cover. Yet I imagine that the subverting part did indeed come from Walsh. While I sense in him a certain affinity for the word subversive, I wonder whether this is the happiest term to use to describe the role of Jesus Christ's followers in God's world. According to dictionary.com subvert has the following meanings:

1. To destroy completely; ruin.
2. To undermine the character, morals, or allegiance of; corrupt.
3. To overthrow completely.

Given these overwhelmingly negative meanings, would it not be better to use more obviously biblical metaphors which see the gospel as yeast (Luke 13:20-21) or mustard seed (Luke 13:18-19)? As salt (Matthew 5:13) or light (Matthew 5:14-16)? To be sure, God stands in judgement on arrogant evildoers and his followers might be seen to be undermining their pretensions. Yet the good news of redemption in Jesus Christ is not a corrupting or decaying influence. It is one of restoring creation to its original goodness -- something altogether masked in the term subversion.