I still think that if Uni were to ever work with Nick again or with Cartoon Network, it'd be really cool if they made it something like Star Tours where it could easily update. As one show ends, just update the film with a new cartoon. I know everyone hated Jimmy Neutron, but a version of that ride with a newer ride system in Toon Lagoon that could easily update to not become outdated could work IMO.
Honestly, SpongeBob and TMNT are timeless enough Nick IPs to where a high-quality dark ride or family coaster could stick around in Toon Lagoon for 20+ years IMO.
I'd also say Scooby-Doo has reached classic status (like Mickey & Friends, Looney Tunes, etc) unlike Popeye and Dudley Do-Right. The franchise gets regular reboots and it's rerun on Boomerang (in its different versions). Combining Scooby-Doo and Laika for a kid-friendly 'spooky' area in the 3rd gate could be a solid land (maybe include the Classic Monsters as the teen/adult attraction). Scooby is still relevant (a new film is set for release Sept 2018 and will likely be a solid hit for Warner Animation)
For Toon Lagoon, I'd like to see:
- SLoP dark ride and a small Sing stage show in toon-based NYC mini-land between Spidey and Sweet Haven/rest of TL
- TMNT family coaster using Space Fantasy ride system and quick-service Italian restaurant (part of Comic Strip Lane and 50% of Dudley area) - serves as thematic link between NYC and Nick
- SpongeBob Splash Battle dark ride and Dora flat ride (a mini-swings along Diego's treehouse) in rest of Dudley area
- Popeye upgrades and Wimpy's upgraded to year-round status
That'd be a good use of the TL space and add in relevant IPs (SLoP, Sing) while also incorporating some timeless IPs (SpongeBob, TMNT, arguably Dora given the 17-year runtime) and keeping a Universal Orlando crowdpleaser (Popeye).
It also gives IOA a water ride that won't get people completely soaked, 3 more major indoor attractions (previously 0 in TL) and gives families with infants/toddlers/preschoolers more to do at IOA outside of Camp Jurassic, Storm Force, Hippogriff and Seuss Landing.
I doubt most of this will happen (SLoP and Sing taking over the TL theater area/Comic Strip Lane makes sense, though), but Toon Lagoon has a lot of potential