previous module is deprecated, and may be removed later on (but not before one year, that is 2012-08-27). in the meantime, it will continue working (although with a warning).
what does it mean for dzil users? well, nothing much, since old module will continue working as is. however, they should better migrate their dist.ini from:
nothing else is needed... for now, since i guess kentnl will continue proposing patches / pullreqs to dzil:*tests plugin authors! ;-)
also, please note that the github repository has been renamed and is now available at a different url. ditto for cpan, since the dist is now named dist-zilla-plugin-test-compile.