Here are my suggestions for bringing back Fishing back from the dead!
Though I do realize that most if not all of these suggestions probably won't be be able to be added until the new client, if at all.
1. Fishing Animation! I hate just seeing my character completly still while fishing, it would be great if there was an animation to go with fishing as it also explains why there has to be a cooldown.(throwing rod, waiting for fish, etc)
2. Better IV's. People are always on the rage for better IV'd Pokemon, one insentive to fish would be because fishing Pokemon could have a -slightly- better IV range
3.Bizzare Rods. i.e.
Shiny Rod - Gives -slightly- better chance of finding shiny Fishing Pokemon
Deep Sea Rod - Could be used in combination with Suggestion 2, gives you a higher chance for finding more furocious deep sea Pokemon.
Exp Rod - Gives you more exp off sea battles when used
Money Rod - Gives you more money off sea battles when used
These could be obtained.off quests.
4. Different Kind of Random Chance. In the handhelds, Feebas for example would only appear in a single tile out of a whole lake, this could be implemented in PWO as well by making a surfing HR into only a Rare or VR, but making it only spwan in a signle or two tiles only, people like taking chances and hoping to get something quick and easy so I think people would use this, once encountered the Pokemon could change to a different tile so it would be random every time.
5. Baits - Kinda of like Bizzare Rods, different baits would let you capture different kind of Pokemon, i.e. Shiny Bait, Dragon bait, Strong IV'd bait, perhaps different baits could be used with Bizzare Rods for different combinations, only difference would be that baits would be used every.time.you fish so you'd have to keep getting.more every time, from Pokemon drops or buying them, (possible.money hole i guess)
6. Rare drops - Have more Fishing Pokemon drop more things, evoultion items, healing items, etc.
That's about it, I think if most of these ideas would be implmented we would see fishing be used a lot more, but that's just my 10 cents.