I'm leery of anything Google says or does right now, but if Google wants us to use this technique, then maybe they won't smack it down.
Moving content to sub-domains is what MC has been saying all along. Doing this isn't something to trick Google, it's what they're telling us to do.
The chances of it working may be less than 50/50, but if it does work, for many of us it's worth taking the chance.
There should be some differentiation between UGC sites and otherwise, though. Sub-domains make a lot more sense in a UGC site where you can split things up by user.