I don't get it. There are just a few broken applications where this doesn't work - Novell's GroupWise, Inkscape and Gimp are the only three I can think off right now on my system. Actually, I believe this used to work in Gimp, they just broke it at some point. So you saying that it doesn't work is just silly.
So the few app maintainers which have been incapable of implementing this just need a gentle push - or a patch. At that point, we can save trees and make the reboot experience nicer - you don't have to loose all your state anymore.
Much more important, the session capabilities are put to use in a far more innovative way: Activities. Being able to save the state of a group of your applications and stopping/starting them based on what you're working on, and even more cool, moving it all to another device, is something really new and useful.
Imagine - you're at work, and are working on a task but don't want to miss the train. Transfer your work (not just the files but the whole session) to another device (say laptop, or tablet, if your desktop is smart enough to adapt to such a device) and keep working in the train!
(granted, the moving of activities from one system to the next isn't possible yet, but managing and using them on one system works just fine)
I think it's time to look at a calendar: yes, it is 2012 and your computer can do more than you think. Trowing around workarounds like suspend are imho just a bad excuse for unwillingness to adopt new, good, useful technologies. The idea that shutting down the computer means loosing everything you were working on is DOS era stuff. Does the fact that MS and Apple can't get their act together mean we have to be similarly restricted?