Link wheel's in the traditional sense aren't effective. The interlinking of the properties are a dead giveaway. I'd say link-pushes (or tiered link building) is your best bet right now. Tiers can work wonders. Create really high quality mini-sites, web 2.0 properties and articles, then have a second tier of backlinks (in volume) pointing to those high quality ones. Then have a third tier where you blast even more volume of backlinks to the second tier. You can even interlink some of the upper tiers, so long as it looks random and natural.