Personally i'm glad they didn't buy 40k. I like 40k but I find SC to be much, much less soulless and much more engaging...
Well, i'm a bit divided when it comes to SC2. I absolutely loved SC since the first one was released, but I feel that Blizzard are getting stale in their stories (it clearly shows on the warcraft license). They reprocess and re-use all the same story tropes and threads that they already used in WoW (we can make so many parallels that it's easy to guess the end of the story just looking at WC3 and WoW).
Coupled to the fact that they don't seem to want to disturb the statu quo of the races, for obvious reasons, and eventually they never evolved. They make you believe they will change and mature, but eventually it's always back to the starting point, and stuff resets and starts again in a different fashion, to a point where it just stretches the suspension of disbelief. "Oh, the terran allied with the protoss, then they ally with kerrigan/zerg, then they fight each other again, etc". Yeah... well.
Now then, I absolutely loved Wings of Liberty, which was even better than SC1 story wise to me. It was absolutely glorious, the innovative take on what you get between missions in the HQ... The story was humoring you and witty. It had depth and was sometimes moving (especially at the start and the end).
In contrast, I found HotS to be clearly underwhelming. The beginning was very promising, we were sold a Kerrigan searching for herself in exile, and then they clearly didn't want her to evolve and... Well. What was all that for? Nothing. I felt it ruined a bit what we got in Wings of Liberty. It remade her into a lot less likeable character. And what about sidekicks and secondary characters? Anthropomorphic zergs that have the depth of an oyster... Overall, once you get your own ship and you are out of the prologue sequence in HotS, it starts to get boring pretty quick, until the end where stuff happens at last...
Honestly, I was expecting something much more akin to what we had in SC1. Playing the zerg and the protoss never felt that less interesting than playing the terran compaign because their characters still felt interesting, and the synergy with other factions kept them interesting.
So... I'm a bit wary of trying the last episode with the protoss, especially as I don't really like the new take they have on them. Now they just feel like space elves... I am unable to explain it well, but the vibe I get from them has drastically changed. I now feel like I see a warcraft ripoff in space rather than the protoss I loved from SC1...