WWE and the wrestling business might have it's major dips. Like they seem to be having currently! But I don't think the business will totally go under. It may never be as good as it once was 10 years ago. However, there is always the chance of improvement by any means necessary.
TNA really needs to step up their game. By this I mean get rid of the six sided ring. Get rid of the older WCW, and some WWE names. Some like Christian Cage for example aren't bad. But Nash and Sting need to be let go. Then begin pushing their younger talent more and more. If they don't do so then the younger names with careers ahead of them. Will get fed up and walk out similar to what some did in WCW.
WWE I think needs to kill off their ECW brand altogether. Begin releasing names in the lower mid card, and lower division as well. Limit the championships back down to 4 or 5. Then either merge RAW and SmackDown again or let the champions be on both brands once again.
Competition is what keeps things alive. Without competition your just going to sit back and not care about anything anymore. That's what WWE currently needs is TNA to step up their game. So they're both fully watchable again, and build up competition between the two companies.
ROH I don't think will ever become a huge company. I look at it the same as I did the original ECW. It's a small company. But with a loyal fanbase. That I think will stay alive for many more years. Possibly if TNA doesn't step up may live longer than them.