This seems to get around the problem brought up by @jandrese above; it’s harder to move a parcel of land to another state than it is to move a trust or tax domicile. I also like the idea discussed by @d_r of a small increase in state income tax, perhaps allowing for the exemption of a primary residence or a small family farm from the estate tax proposal.
As appealing as it sounds, I’m not sure if this initiative will pass as-is. Putting aside the usual objections of wealthy people and Libertarians, the whole student debt industry is going to unleash hell on this proposition. This is the problem with doing these things by ballot proposition, which tends toward simplistic solutions and allows for simplistic objections (“this will take your house from your kids!”), with the winner often determined by who has the most to spend on TV and billboard ads.
However it turns out, the application of funds to allowing more young Californians to get a post-secondary education without getting mired in ruinous and endless debt is a worthy one that will make a prosperous state more prosperous in the future.