I would have to think Tomorrowland is next on the list of upgrades. If a CarsLand style of ride is ever built at DHS, there's no reason why they'd need to keep the Speedway. That's a heck of a lot of usable space for one attraction that's way past its prime (even though it's one of our family favorites).
At the same time, I've always kinda thought of the pathway between the Speedway and Cosmic Ray's as kind of a transition area from one land to the next. There isn't a lot to look at, the Speedway isn't anything I'd consider as futuristic, Cosmic Ray's is pretty generic from the outside, and some of the FL style begins right across from Cosmic Ray's. So for me, the long walk from TL to the tea cups works perfectly to slowly transition from TL to FL. :shrug: