All the bugs and balance fixes on Lordaeron will also be implemented on Deathwing/Ragnaros upon its release. Saying Lordaeron will be the best wotlk server yet is therefor merely an opinion as some people doesn't prefer 1x server.
Anyway, I myself will most likely switch from Deathwing to Lordaeron, mainly cause I play this game a lot and therefore 1x server would suit me best, also because I like the decision Kaer has taken with making the server progressive (releasing vanilla, tbc and wotlk material separately).
I think a lot of people are excited about Lordaeron, the server will most likely be very full and active the first few weeks, but it will no doubt die down and leave only the most hardcore players once people realize what 1x server actually means (most people give up/lose interest before they reach lvl 30).
Still havnt decided what class to roll or faction, but having played Horde, and only Horde, I am very keen on trying Alliance. I also never played either warrior or priest so I suppose I'd be rolling one of those!
See you there! :)