It depends on the seat you end up with. Most seats are sideways now, with some that are doubles facing forward. A lot of dh's just stand towards the rear of the bus, with the folded up stroller, so as to get off fairly quickly and get it unfolded.
The thing I hate is when a family of 4, has each person take a seat, even if a child is the right size to sit on mom's lap, and then they put the folded up stroller on another seat. And they don't seem to much care when others get on and have no place to sit. I actually overheard one dad (who had done exactly as I said here) respond to a request to move the stroller off the seat with an 'Oh, it takes up less room on the seat than on the floor..it's better where it is.' Are you kidding me??? They had one child who was probably about 3 but who insisted on crawling all over the seat and trying to get to mom, but they kept tellinig him to sit down and stay in the seat. Why mom couldn't just hold him and free up a seat was beyond me.
I really wish Disney would come up with a storage area for the strollers.