I am wondering: is there still an advantage in having fishing skill 450?
Take an alt with no skill to a level 70+ zone and see what you catch when you don't fish from the pools. I'll save you the trouble - sick fish, tangled fishing lines and chunks of ripped sails - ie/grey garbage.
Max fishing isn't needed if you're not much of a tradeskill/cooking person, but it's still worth working on - just fish while waiting for a boat or BG or instance and you'll be maxed out in no time.
The new fishing dailies are a great boon to non-maxed characters since part of the reward is an increase in skill - I got my bank toon doing the fishing and cooking dailies (Horde - Ally ones suck with a capital S) and it'll have a maxed out cooking skill in no time (plus the free meat from the boxes and occasional bonus potion from the bags).