From what I have seen with DDO, I have played DDO off and on since before and after the F2P changes there, it was implemented in a very good way. A way that is similar to other F2P games yet very different in that it is not an imbalance and free players are able to have a blast as well as the paying players. I actually enjoyed DDO much
(and I emphasize much) more than I did prior to it becoming Free to Play. Turbine knows what they are doing and, in my opinion, are one of the few gaming companies left that honestly care about their game and its communities equally, so I am confidant that this change will be not only good for LotRO but implemented in a good way, similar to what was done with DDO.
With DDO, subscribers (VIPs) get access to all new content automatically. Free Players had to spend Turbine Points to unlock more areas and quests as well as unlock more character slots and the like.
I am sure much of the LotRO Store will be similar in aspect to DDOs, yet different in its own right since there are many differences between LotRO and DDO.
Here's a overview of what DDO's Store has to offer:
http://compendium.ddo.com/wiki/DDO_Store_Guide