NathKnave from WarcraftPets brought up something that rekindled my curiosity and concern abut it. What will happen to the pets/items that are LFR exclusive once the next expansion comes out and toons out-level MoP LFRs?
Currently the system works in a way so that once you reach a certain level, you can no longer queue for certain dungeons. You need to head to the portal and physically zone in. Will this also apply to LFR? If so, we'll be out of luck since there isn't a way to physically go to a portal and zone into a LFR raid. A normal or heroic raid, yes. But LFR? We could fly around in the nethervoid forever and still not find a way into LFR. :P
With a pet and even uniquely colored items (for xmog lol) being exclusive to LFR, IF LFR follows the same model as dungeons, these vanity pieces are going to be very rare come next expansion. We're going to have to rely solely on alts of appropriate level. Even then, the queues will probably be painfully long since there won't be as many people queuing up for LFR at that point. Not only that but since the items are soulbound, running LFR on your alt does nothing for your main unless the items are BoE or account-wide.
Hopefully they will become available through some other means, such as a vendor. Or maybe we'll still be able to queue into LFR once we've reached the next level cap. I'm pretty doubtful of that though, since that would defeat the purpose of having LFR for each tier.
All of that being said, it doesn't mean we should panic and rush to do LFR on every eligible toon or spend a ton of gold to buy the pet right away. I'd like to give developers the benefit of the doubt that they'll implement something to cover all bases eventually.
Still, it doesn't hurt to do LFR each week on at least your main for a chance at the Living Fluid. :P