Make Domino free to install and use. Maybe restricted to web access, but IBM can always charge for the client...
The Domino web server offer some unique and extremely powerful development features but when developing new online applications the user licences will put off most developers and startups. There are many other interesting platforms out there that are in direct competition with Domino (as a web app server), Ruby on rails and Django just to mention the two I've had a closer look at. But when compared to Domino they both come out short... But FREE!
So, my suggestion for IBM is to FREE Domino from its licence chains so it can live on and not just slowly fade away and die.