I think any plan for a second tier would involve some form of promotion. The issue is possibly if the promotion should be in that year or the next year, I assume the teams would want to get into the A championship in the same year, which means they would have to come in at a later stage of it.
But I think the failure of things like the Tommy Murphy cup and similar isn't because of the GAA or the players, it is just because of the public. If the games got decent crowds they would have elevated themselves naturally. The GAA can't make a game a 'big game' no matter what they try, if only 1500 people are going to it. You only have to see some of the back door games now, the Limerick football one at the weekend for instance, the ground seemed completely empty. Now that was a pure knock out game with loads at stake for the teams, yet no one was prepared to go to it.
Unfortunately it seems most counties only have a small enough core support and the rest is just of the event junkie variety. Unless they see a Dublin or a Kerry in their immediate future the majority won't go to games. Somehow it is this mind set that has to be changed to make anything else successful, and strangely the league is actually getting close to doing that. The last weekend of the league is drawing decent crowds across all divisions now.