In late...but random ideas:
* The hobby is getting inundated with products of various quality from all over the world and is really crying out for some sort of organization that maintains accepted standards (like Underwriters Labs for electrical devices) and gives a "stamp of approval" to items that meet criteria for safety, construction, performance, etc. Would love to see something like an "American Aquatics Association" or "International Aquatics Association" formed to drive levels of quality and standards into products. My bet is that people (especially beginners) would be willing to pay a premium for "approved" products.
* In a similar vein- would like to see formal breeding standards (and ethics) become part of the hobby. I see a lot of posts across the internet from rank amateurs looking "to make some extra cash from the hobby by breeding fish" or simply "I wanna see if I get these fish to breed". As others in this thread have noted, we're seeing strains of fish (e.g. Guppies and Bettas) that are getting weak and disease prone at an alarming rate due to inbreeding. Dog, cat, etc owners seem to generally agree that uncontrolled breeding and/or "puppy mill" type breeding isn't OK (how often have we seen the "spay and neuter your pets" message?) ...unfortunately the majority of this hobby seems to either not comprehend that's what's going on or is choosing to ignore it.
* Step one to me for any newbie is "understand your tap water"- it's natural parameters will dictate which species will do their best with a minimum of needing to become a "mixologist" of additives, buffers, supplements etc. I'm still floored that I haven't come across a pet store yet that gives out free dip strips to people so they can test their water before buying fish to help guide them on which fish will do best in their water.
* When I was a kid there was clothing called "Garanimals" (actually - it looks like they're back) which had a system where when you matched symbols on the tags of pants, shirts, etc. you could be assured that you wouldn't be creating a fashion faux pas. Seems like the hobby is crying out for a system where newbies can easily match fish species A with compatible fish food A with compatible tank size A, etc. to similarly remove confusion, mystery, and disapproving feedback.
* Dealers could do a lot better job of bundling packages for new fish owners. Not just full aquariums, but the accessories. Just bought a Betta? Here's a package with a net sized right, water conditioner, food, treats etc. I was in a pet store the other day and came across a 7 or 8 year old kid and parents that were buying his first Betta and they were completely overwhelmed by all of the different food choices. They still had yet to repeat the process to pick out conditioner, etc.