Unfortunately, the flip side of that coin is that change can be taken too far. Change can alienate players who no longer feel attached to the game -- and no need to stick around long enough to relearn how to play something they used to love. It's a fine line to walk between changing enough to keep things new and not changing so much that your audience is pushed away... and it's arguably a line Blizzard crossed when many of the game's mechanics turned upside down in Cataclysm.
Is Blizzard doing the same with the upcoming Warlords of Draenor? With the beta in a constant state of flux, it's hard to tell -- but if we look back on the tumultuous era of Cataclysm, maybe we can learn something about just what these big changes mean for World of Warcraft.
During Cataclysm, I played a holy paladin -- and had since Burning Crusade. Having played since before dual specializations had been implemented, I tended to run holy whether I was soloing or healing in a group with a spec and gear that focused on maximizing my crit and using holy spells whether I was taking out enemies or healing allies. Before dual specs, this was just what healers did and I found it a lot easier to play as a plate-wearing holy paladin than I had as a cloth-wearing holy priest. It wasn't an optimal playstyle, but I'd never had much interest in the class's retribution spec and since I was geared for and accustomed to holy, I stuck with it.
But Cataclysm changed paladins a lot. In addition to removing the traditional talent trees from all classes, it shook up the way paladins healed a lot and added a new holy power resource their abilities needed to draw on. Logging in for the first time during Cataclysm was a shock: I no longer recognized the buttons on my button bar, I had a new resource system to figure out, and some of holy's soloing ability had been removed. I struggled for a while to relearn my class, trying to spec ret to solo as I seemed intended to. However, being geared for holy, retribution was an even worse soloing spec... not to mention that it wasn't a style of play I particularly enjoyed, so I found my way back to holy. Even soloing, slowly, as I was accustomed to, as holy grew increasingly problematic because quest rewards simply didn't offer gear for holy paladins.
The character was sitting in Hyjal, equipped with a mix of mail and leather because of a lack of plate quest rewards with intellect. Once-collected armor sets were gone because I'd abandoned the character before transmog and didn't have the bank space to keep it all. (Though, fortunately, early Cataclysm gear didn't have the colorblind clown look of early Burning Crusade gear.) I'd missed playing this character, and especially missed the feeling of invulnerability I'd had as a holy paladin -- though I couldn't solo quickly, the character was very difficult to kill with plate armor to soak up damage and plenty of healing to deal with damage taken. This time, I didn't even think about picking up ret: instead, I looked into how to solo with a holy build.
Holy soloing still isn't exactly something Blizzard seems to be encouraging... but there are a selection of spells, talents, and glyphs that offer you to trade off holy healing utility for holy damage utility, even though you'll go entire talent tiers with nothing of use to such build. It's never going to be a good DPS spec and once you pick up the right talents and glyphs it's not even a very good healing spec anymore. But it allows me to play the game in a way I always enjoyed playing it -- despite the fact that the game has changed quite a lot since then.
The moral of the story? Change is coming, but it's not the end of the world. If you're in the beta or reading about the beta and don't like something you see, don't panic: comment. Let Blizzard know what you think in as clear a way as possible, because the game is always changing based on player feedback. Even when changes seem big and overwhelming, many things about the game world stay the same -- and you might find yourself on the other side thinking it's not so bad after all.