Please be aware that with the release of the pre-expansion 5.0.4 patch on Tuesday, August 28, all raid lockouts will be reset. This means that you will not be able to extend a raid lockout beyond the week before the patch release.
For most of your stockpiling and preparation, this doesn't mean much. We won't see pandas or Monks or leveling content until Mists itself actually launches on September 25th. I would have some heirloom enchants and other leveling stuff ready for people who roll alts to check out the new talents and mechanics, but it won't be the explosion of alts we see when Mists launches.
However, the changes to glyphs and inks should be going live with 5.0.4. This means that Glyph of Frostbolt and Glyph of Shadowburn will become Faded Glyphs. If you have any of these left, now is the time to try to get rid of them. As the patch gets ever closer, anything you can get for these over the 50 silver vendor price of Faded Glyph will be more and more appealing.
Similarly, come 5.0.4, you will no longer be able to trade down Blackfallow Ink for the lower level inks. The ink trader will only trade for the new Ink of Dreams, which won't actually be obtainable in any way until Mists launches. Your only source for inks at that point will be the lower level herbs themselves, which are often cheaper, but not available in the mass quantities that Whiptail and Cinderbloom tend to be.
Blackfallow Ink still won't be entirely useless, as the Mysterious Fortune Cards continue to be a viable market on many servers (though I wouldn't be surprised to see it crash temporarily as people who didn't trade down before the patch scramble to dump their Blackfallow Ink). But if you want to sell glyphs come 5.0.4, please make sure your Blackfallow Ink is traded down no later than August 27th.
In fact, I would highly recommend either making your glyphs now or at least trading your inks. If you play it close and leave it until the night before, who knows what may come up that night to keep you from logging on?
If you're going to craft glyphs ahead of time, I'd recommend starting with a stack of everything (minus the two that will become faded, of course). With most of the glyphs either getting new functionality or becoming something new entirely, trying to guess which specific glyphs will be in demand is something I don't think any of us want to bet on.
If you prefer to have your inks ready and just craft as needed after the patch, Jim at Power Word Gold has a very handy Ink Distribution Calculator. Just plug in the amount of Blackfallow Ink you have, and it'll tell you how many of each ink to trade for, given the amount of glyphs currently crafted with each ink type.
There's still time left to get in on the glyphy goodness, but only if you get your act in gear right now. Work hard, use the tools you've been given, and before you know it, August 28th will be here, and we'll all be making plenty of gold while we wait to destroy Theramore.