With patch 5.4.8 we're seeing a new way to achieve an old goal - allow players to get further in established content while it remains the most recent content available. In essence, with this patch, we will be able to buy slightly increased ability to progress with valor points. This isn't new - it's what the item upgrade system has always been.
I've been thinking about the new item upgrades and the Deeds of Valor since they were announced. I haven't been able to play WoW as I'd like lately (health reasons) but one of the things that immediately came to mind when they announced Deeds of Valor was that this was an entirely new way to nerf raid content at the end of an expansion. Instead of a progressive buff to the players, or a progressive nerf to the bosses, we're seeing a mechanical way to spend valor points to gain the same ultimate aim. Making it possible to trade in your Timeless Coins for valor points is a good way for players who are flush from constant Timeless Isle grinding to convert them to something useful, and allowing players to upgrade items an additional 2 times (for a total of four upgrades) serves to nerf content without nerfing it. Everyone will be stronger, will hit harder, will have more mana for heals.
I have some opinions about this, of course. Others have already expressed theirs - and to be fair I accept the basic premise that these are quality of life changes that will cease to matter in patch 6.0. And I'm okay with that, because again, I see this primarily as a way to nerf Siege of Orgrimmar without actually doing so. It gives us another valor dump, of course. But with changes like Heart of the Valorous (which won't be live when 5.4.8 drops) it feels as if valor itself is being made into a progression mechanic.