I don't think Saas will replaced by something else as these are solutions to so many problems and help in improving efficiencies and productivity , decreasing human errors and use of paper, etc. I
was searching for Saas companies these days and came across a company Cerebrum Infotech, they have developed so many apps and management software which can be helpful for many industries. These are E-Marketplace apps , Education Management System, Ride and Rental App ,Fleet Management System ,etc. They have also launched CereKart, which is great for any delivery business.
I think the future of the SaaS market is to continue to automate what human beings are doing when it comes to data mining, transfer and management. When you look at any great SaaS product it really is a piece of code doing what a human was being paid to do. I think the trend will continue and allow humans to do more valuable work on top of the SaaS stack.