This former FVist is claiming that the Federal Vision was a stepping stone to Rome (link). The big "yeah, but," is that obviously the step before the Federal Vision was a Reformed Church. In any event, stones should not be blamed for those who step on them, and it seems somewhat unfair to blame Doug Wilson for the path of any given former member. It's fair to say that a person becomes Roman Catholic not because they follow DW too much, but because they are attracted only by a part of what DW has to say.
Still, that is really the only way for the logical progression to work:
Reformed -> Federal Visionist -> Catholic
Of course, that said, many people bounce around alot before settling on letting the Vatican make their doctrinal decisions for them. So I wouldn't be surprised in time to see some poor fellow make a hop from FV to TR to RC.
Thanks to the Trinity Foundation (this one not the other one) for bringing the post to my attention.