Fun fact about me, I love World of Warcraft. I've been playing since 2010, mainly with a DPS Warrior and a Disc. Priest. 

As some of you guys might now the next expansion for WoW, Warlords of Draenor, is coming out at some point in 2014 (or early 2015). If anyone here plays they know that MoP wasn't really the best expansion in terms of number of subscribers gained. In fact, WoW has been losing an absolute buttload of subscribers ever since Cataclysm. 

Will WoD save Warcraft? Or is WoW doomed to fade into obscurity due to old age? 

Right now WoW is still pretty much the gold standard for MMORPGs but I think that's soon to change, and I'm honestly not sure if it can be saved at this point.

Well, seeing as there are not many real competitors to WOW, despite all the other new entries to the MMORPG genre, I feel like the game will still last for at least another three years (don't take that as a basis for anything, I could be totally wrong). 
I used to play World of Warcraft, but I had to stop due to financial issues, lack of a credit card I could use, computer not being able to support new updates, etc. I stopped a month after I got the Burning Crusade expansion, and that was around the time Cataclysm came out, so I might be rather out of the loop.
Correct me if I'm wrong, but I am pretty sure that the player-base has been declining (active players, that is). Though the declining number isn't significant enough to kill the game off or force them to go fully F2P, so I think that WOD could only stand to help out WOW. Unless everyone thinks that WOD is so horrible that they choose to leave the game entirely, it will only increase the player-base, or help to at least stabilize the numbers.

Subs isn't the whole picture, they've added a number of new services that do not undermine the legitimacy of the subscription model.

Most notably, and somewhat controversially, you can purchase a Level 90 boost for a fresh level 1 toon for $60 right now - and you get a complimentary boost by purchasing the expac. Some would say that's P2W, but as long as you don't get any endgame advantage whatsoever I think this will be a successful addition to the game. WoW is not going anywhere anytime soon. So long as they retain any semblance of stability in subs at all, they're going to keep coming up with optional paid services that will pad the coffers for years to come.

In terms of quality, this expac's pve content has been very strong. The raids as a whole far surpassed what we saw in Cata, both in terms of quantity and quality. The intro of CM dungeons was a huge step in the right direction to restoring challenging 5Man content to the game, and we saw lots of other good things like them finally merging dead realms to restore some community to those servers. 

There were issues though. The "Legendary" cloak quest chain, was tedious and unnecessary. It makes alt toons very hard to maintain, and it's cumbersome for players returning late to the party to raid - not to mention the fundamental flaw in the concept of 'legendary' being compromised if everyone both can and is expected to get it. Class balance was really bad throughout the expac.

Warlocks were just way too good for both Tiers 15 and 16. I've never seen one dps class enjoy such sustained dominance since I started in early Wotlk - Top or near-top sustained singletarget/aoe, burst, single/aoe, survivability, and excellent utility. No weaknesses to speak of at all for this class, like the hard-hitting Mage's lack of survivability/utility. Why even play a Mage if Locks can do everything a Mage can, except more and better? 

Finally, and this is the real kicker, we're six months into Siege of Orgrimmar already, and the tentative release date they mentioned is 'before Dec 20, 2014'. They bled a frustratingly high number of subs when ICC dragged on for an entire year. Why they would repeat that, is just beyond me.

WOD looks very good, just because they didn't add a new race or class there's still going to be a lot to do I reckon. But this wait is brutal, as a new GM of a 13/14h raiding guild, I'll be challenged to retain my playerbase for that long after we down Garrosh. These kinds of waits are just guild killers.

I've heard rumors about it possibly going F2P then shortly after the rumors sprung up it was immediately shot down by staff stating that WOW wasn't meant for free to play. Yes they already have a free to play option but it only lasts until level 20 and various things being closed off. In my opinion making the game completely free to play would revitalize WOW. Obviously they should make stipulations and tweaks to ensure they still make munny. When players had the idea pitched to them, they didn't really like the idea of it going free to play, I forget why specifically.