As smartphone storage capacity grows on average with each passing year, many manufacturers have begun to abandon the microSD card slot on flagship handsets. Google itself has taken multiple opportunities to trash expandable storage as a "messy" feature that, from the standpoint of the people who actually develop Android as a profession, is not worth the problems it creates.
This has been a major point of contention between Android enthusiasts and Google, particularly when it comes Nexus devices. Not since the Nexus One has a Nexus-branded handset or tablet been equipped with expandable storage, and Google has shown no sign of backpedaling on its hardline stance. At this point, the alleged technical complexities probably don't even matter - it's obvious Google holds a philosophical grudge against the SD card, and that it does not plan on "seeing the light" any time soon.
Manufacturers, however, have largely ignored Google's crusade on the pinky-sized storage device. Sony, LG, and perhaps most notably, Samsung, continue to ship most of their high-end phones with microSD slots, with Samsung having become the poster child for "user choice" in this debate. It has even recently updated the Galaxy S4 with the legacy apps to SD support that Google abandoned after Android 4.0.
However, I would wager that the OEMs still hanging onto the SD card slot option do so largely as a way to punt on the question of included internal storage. A microSD slot is much cheaper than adding another 16GB of space to a device, and it leaves buyers to bear the cost of increasing storage. Rather than risk producing a second model of handset with 32GB of included storage that may not actually sell (or paying to up the entry-level model to 32GB), it is far easier to include that microSD slot and point to it dismissively when complaints about capacity arise.
Samsung is somewhat of a rarity here, in that it does produce a 32GB version of the Galaxy S4 (and supposedly a 64GB edition may go on sale internationally), but in the US, two of the four major wireless carriers have simply chosen not to stock it - probably because it wouldn't sell very well. It will be interesting to see if the much-hyped Moto X has a microSD card slot, being the first piece of hardware developed by a Google-owned Motorola.
As the owner of a 32GB HTC One, I can't say I miss the SD card slot. I don't store much music locally (what is stored locally is just streaming cache), or keep many large games or videos on my phone at any one time. Even most 16GB handsets don't make me feel the storage crunch all that much.
So, when it comes down to it, where do you stand on the issue of microSD cards? Are they necessary no matter what? Is there a threshold at which you'll be willing to give it up? I've attempted to include a variety of choices in the poll below, so cast your vote and let your view be known in the comments.