For the lobbying, that came into force into July 2008, so it's been a couple of years.
As to the costs, what I've heard is more anecdotal evidence—non-profits deciding to look at whether they're hitting the “significant amount of duties” test. Some have determined not to register. These are firms that might have registered if they felt they were hitting 15%. Re-looking at it, they're choosing not to register, because of the burden. If they don't need to register an initial registration, then they don't have to file monthly communication reports.