The FAA fortunately left the limiting language out of the new 51 percent rule that applies to aircraft owners building their own planes.

Here is the FAA rules for amatuer built aircraft

Here is the link to the FAA Advisory Circular 20-27G, on Certification and Operation of Amateur-Built Aircraft, which tells amateur builders on how to properly certify each step of the building process and help those guys, like me who would have to do the builder assist program to not only finish, but to get it right!   According to the rule existing kits will be grandfathered in under the new rules.

Thanks to our GA lobbists at AOPA and EAA for getting these things done right for us pilots and aircraft owners!