Working for an Android blog has lately meant looking forward to a single device: the Samsung Galaxy S III. Samsung has gone to extraordinary measures to keep its design and features secret, and as a result we’ve got almost nothing beyond rumors and speculation to go on. But since the Galaxy line has done phenomenally so far, we can’t help but have expectations – after all, odds are pretty good that no matter what Samsung reveals on May 3rd, it’ll wind up in the pockets of tens of millions of Android users all over the world.

I don’t have any inside info on the Galaxy S III, and anyone who tells you that they do is either lying or about to be fired. But what I hope for isn’t anything in the range of gigantic screens or space-age build materials. Believe it or not, I think that plastic is a pretty great way to build a light, sturdy phone, and my experience with LG’s Optimus LTE variants and the Galaxy Nexus has taught me that cramming more and more pixels into a screen smaller than five inches doesn’t necessarily make for a better device. I’m not even looking for unencumbered Android, as seems to be so vital these days – as loathe as I am to say it, TouchWiz and Sense have become stable and useful, and in any case, I’m a handy enough guy with a bootloader that they won’t be around for too long on any device that I own. I don’t even care that much about capacity or SD cards, since I never fill up my devices and all my media’s in the cloud.

No, the one thing that I want from the Galaxy S III is something that everyone desires, from every device that they own: longevity. The Galaxy Nexus’ poor battery life (when compared to other phones) is one of its grand failings, and the reason that the “pure” Google phone that I bought with my own money sees less use in my pocket than the Motorola DROID RAZR MAXX review unit. At the end of the day, your smartphone had better be ticking… anything that isn’t is just a pretty piece of excess.

Unfortunately, the deck is rather stacked against the Galaxy S III in the battery department. Consumers are demanding thinner and thinner phones, while seeming to completely miss the fact that this means batteries can’t grow to meet the power needs of faster hardware and wireless standards. Samsung seems ready to give it to them. And while the Galaxy S II (a phone that is in so many ways similar to the Galaxy Nexus) gets great battery life, the addition of Verizon’s CDMA-LTE network seems to cripple the Nexus, even with the slightly extended battery that I use. If rumors of a phone with a gigantic HD screen and a slim body are to be believed, then hoping for a battery with 2500mAh or more would seem to be in vain.

It’s a shame, too. While manufacturers and software publishers are trying their best to maximize available battery life, the simple fact is that power technology isn’t advancing anywhere near as fast as other segments. The solution is just to get bigger and bigger batteries, something that the “new” iPad demonstrates: its physical battery is about twice the size of the battery in the iPad 2, enabling it to keep an acceptable battery life even with a hi-res screen and LTE. I’m no Apple fan, but credit where it’s due. Motorola, a company whose locked bootloader policy has drawn the ire of Android purists everywhere, seems to be on the right track as well: via some downright amazing feats of mechanical engineering, they stuffed a battery almost double the standard size into the DROID RAZR MAXX, making it one of the most genuinely useful LTE phones on the planet.

I’m sorry to say that I don’t have any confidence in Samsung’s ability to engineer past the power problem. If there was an easy answer, we’d have it by now. And for all their charms in other areas, Samsung has begun to show a definite preference for style over substance. The idea of a “Galaxy S MAXX” just doesn’t fit their current brand image, though I’ve no doubt they’d sell millions of such a device.

I’ll be on the edge of my seat for Samsung’s presentation, like many of you. And I’m certain that I’ll be wowed by their latest and no doubt greatest screen, and I’ll “ooh” and “ahh” if they manage to slim their flagship design down to seven millimeters. But my respect and more importantly my dollars will go to the first Android manufacturer that can get me a 4.3-inch or larger screen, an unlocked bootloader and a battery that doesn’t have me checking to make sure I’ve brought my charger on a trip to the grocery store. (You were so close, Moto!) I hope it’s Samsung, but I’ll settle for anyone.

Speaking of Samsung’s event, Android Community will be there live to cover it. Join us for the live blog on May 3rd. That’s enough from me – what’s your must-have feature for the Galaxy S III? Let us know in the comments section.