I still think you’re going to cause a new form of sculpting, where people will remove links from their pages other than using nofollow, in hopes flowing PageRank to links they think are important. You’ve said number of links matter — and that nofollow doesn’t reduce those links — so some will keep chasing after whatever extra oomph may be out there.
In an effort to manually control the flow of PageRank among pages within a website, many webmasters practice what is known as PageRank Sculpting—which is the act of strategically placing the nofollow attribute on certain internal links of a website in order to funnel PageRank towards those pages the webmaster deemed most important. This tactic has been used since the inception of the nofollow attribute, but may no longer be effective since Google announced that blocking PageRank transfer with nofollow does not redirect that PageRank to other links.
The flood of iframe and off-page hacks and plugins for WordPress and various other platforms might not come pouring in but I’m willing to bet the few that come in will begin to get prominence and popularity. It seemed such an easy way to keep control over PR flow offsite to websites you may not be ‘voting for’ and afterall, isn’t that way a link has always represented. It would seem Google should catch up with the times.
PageRank was developed by Google founders Larry Page and Sergey Brin at Stanford. In fact the name. PageRank is a likely play on Larry Page's name. At the time that Page and Brin met, early search engines typically linked to pages that had the highest keyword density, which meant people could game the system by repeating the same phrase over and over to attract higher search page results. Sometimes web designers would even put hidden text on pages to repeat phrases.