Time for some totally unfounded and idle speculation on the future of LotR. Well, maybe not totally unfounded. I believe the developers have Dunedain, and possibly even Noldor, planned as races which players will be able to "unlock." While I have wondered about such a possibility since I came to the game, it was ony over the last few days that I began to see signs it may be true.
My evidence, such as it is, is very circumstantial and is based on the fact that two regions seem likely to open up which would be excellent Newbie Areas for those races. That is, all the current races in LotRO start off in their own area -- the Shire, Archet, Thorin's Halls, what have you. And there are indications that the developers are working on a settlement in north Eriador where the Dunedain hide out and store their lore. This would be the place Aragorn's mother went to after her son was born, and where he visited her before her death. The corresponding Elf region is, of course, the Grey Havens, which are located on the Eriador map but which we cannot yet reach thanks to swarms of Goblins and intimidating walls.
I understand that unlockable classes did very poorly in Star Wars Galaxies, where Jedi have become so common that the setting has been strained beyond the breaking point. (If it is any consolation, everyone wants to play Jedi in the tabletop game too. I doubt the new "Saga Edition" of the SWRPG will do anything to change that.) But in other games, and I am thinking specifically of City of Heroes here, unlockable race/classes have been implemented successfully.
The folks at CoH created an alien race (two of them actually) which had the ability to shift from one role to another -- this was their primary advantage. So a Khledian could be a tank or a blaster or what have you, depending on need. However, where the game designers made an error with these races was by making them measurably better in a fight than their non-alien counterparts, and balancing this out with special villains who only appeared when one of these aliens was on the team. I never agreed with this policy and still don't -- it makes the Kheldian into the center of attention as everyone on the team has to target that one special bad guy. I am all for allowing players more flexibility, but I am not for allowing them more power.
One other thing the designers at CoH did right was that the Kheldians actually gain more power when they have non-aliens in their group. This encourages the alien players to group with ordinary players, and discourages the "All-Alien Alliance" of snobs who refuse to play with anyone else. Of course, the alien characters also had some new game content -- new missions which other players could not get to. Not an overwhelming amount, but a steady quest line which could take a player through a satisfying portion of each character level. To unlock these classes, the CoH player had to reach 50th level (the game maximum) on an ordinary character. This usually took about 6 months to a year for roleplayers, though power-leveling techniques can no doubt accomplish it much faster.
So unlockable races can be done successfully. What remains to be decided is what form those races might take.