This is actually a fantastic method for introducing scenarios! Part of my problem with the Theramore scenario was always that there was absolutely nothing to root it into the game -- it was simply an option on a random game menu with no real meaning behind it. Having Lorewalker Cho tell the tale gives players a background on just what exactly they're setting out to do, and a reason for doing it. Mind you, digging up stories for a pandaren may not be the ideal fun time for some players, but it still serves as an introduction of sorts, something Theramore desperately needed.
In addition to an introduction, there's a new way to queue up for scenarios. Lorewalker Cho has left a pot of his special dream brew on a table in the Lorewalkers area. For Alliance players, this may sound a little familiar -- Cho's storyline in the Jade Forest has Alliance players construct a dream brew in order to help try and track down Anduin Wrynn.
Clicking on the dream brew will allow you to queue for one of several scenarios. In addition to the new scenarios, A Little Patience and Dagger in the Dark are both available options. While I'd originally thought that perhaps one needed to complete both 5.1 scenarios in order to access the 5.3 options, this doesn't appear to be the case -- the content simply isn't open for players at the moment.
However, at this time it appears that you cannot simply waltz into the new scenarios. Some of the new options imply that an ilvl of 496 is required to be eligible for the content. Whether or not this restriction makes it to live is yet to be determined -- this may simply be a PTR restriction, and we've got no real way to tell for certain at this time. Keep in mind that the things you see on the PTR can and will change as the PTR progresses.
But honestly, I'm not really upset by the ilvl requirement. Heroic scenarios are a nice option that offer the ability to make scenarios a little more challenging again, and the ilvl requirement implies that the new scenarios are also going to be a bit of a challenge as well. It's a given that players will find the normal scenarios easier and easier as time goes on. Ramping up the difficulty, offering new rewards, and making slightly more difficult scenarios as time goes on helps to make sure that that content isn't going to be outdated before the expansion's end.
We'll have more for you once the scenarios are actually playable. But for now, you can look forward to the Lorewalkers area having some use again, and some new stories from Lorewalker Cho as well.