This would be good for a couple of reasons. The sooner code gets put on Ragnaros the sooner heavy donors like myself can feel that we are supporting a large scale change that will benefit our experience and that we're being respected for our financial support of these servers. Let's face it, I only care about whether my cash will benefit ME... seems selfish but everyone who spends money wants to feel they are getting increased VALUE. Broken quests and endgame feels like we aren't getting the attention we deserve lately. (no updates since June) Not a complaint. Just trying to help you guys see my perspective and I hope you don't ignore it.
I personally don't have time to level a low level character and leave behind my stable of BIS characters I've donated for, so I won't be rolling on Lordaeron.
A huge part of the good experience on Warmane for me has been the increased rep rates and gold drop increase. It just seems more fun to me.
We have a thriving community that is engaged and ready for new content like Malygos and Ulduar fixes so guilds can do the Yogg+0 encounter and get achievements like Firefighter and other notable achieves. The second main reason we should see code ported to Ragnaros etc is to help and be a part of the Lordaeron experience without actually having to feel forced into rolling on that realm. Some of us feel kind of left out... but you know I do submit a lot of bugs to the bugtracker but it's probable that the bugs I've submitted are already fixed in the new core, so it's not a good idea to maintain two code bases -- it's unpractical. I feel like all my bug tracker submissions have gone completely unnoticed... and there are many.
Working on two code bases isn't logistically practical and it's detrimental to the overall player experience; let's get all the realms on the same base and update them at the same time with all the wotlk players and not just a select few who have enough time to spend doing 1x and no-donations.