RIM’s day of reckoning is almost here. Tomorrow, the once-mighty Canadian company will officially unveil its new BlackBerry 10 operating system, along with new hardware. It’s a chance at rebirth, reinvention, and getting out from under its walking corpse reputation. But for that to happen, RIM needs to prove it’s back on the right track.

Here are a few of the things we’ll be looking for. If they all fall into place, we might just have a comeback on our hands. If not? Lights out.

BlackBerry software has never been great, but it’s almost always been efficient. Get in, get out, reply, forward, flag. Before any other features or functions, these are the things RIM has to lock down with the new QNX-based BB10. We’ve seen the makings of a highly efficient and thoughtful design in the demos—especially at CES—but software always looks good in demos. Let’s see how it fares once it’s loaded down with apps and gets blasted with a few thousand emails over the course of a week.

Further, launching a whole new operating system with a whole new code base is always going to run into some bumps along the way. But launching it into one of the most widely adopted business communication platforms means those bumps better be damn small, and smoothed over in a hurry.

We saw how widely a BlackBerry/BES outage affects the business world with the great BlackBerry outage of 2011. That went a long way to dinging RIM’s reputation as a rock solid, reliable service. It was Sylvester Stallone punching thousands of IT departments in the crotch at once. And it simply cannot happen with this launch. BB10 has gone through a tortuous—and extensively delayed—release process, so a lot of bugs should presumably have been sussed out. But there are always more flaws and vulnerabilities waiting in the tall grass.

The Z10 has to be as great as it looks. Has to. There’s no room for an aw-shucks-we’ll-get-’em-next-time slop here. The renders we’ve seen are gorgeous, but now we need to see and touch and use it in person. All of those software usability questions from above roll into this, but there’s more than that. The Z10 is RIM’s shot at being desirable again, in the way iPhones and GSIIIs and Nexus 4s are desired.

But it has to go deeper than the Z10. RIM’s Qwerty offering needs to be on point as well. There isn’t too much to worry about here, since the BlackBerry Bold 9900 was the best BlackBerry ever made. But we’d still have concerns about how the new software will interact with RIM’s tried-and-true hardware. Will battery life take a hit? If the Qwerty models are using legacy designs, will there be a notable performance difference between them and the touchscreen versions? And most importantly: How will RIM navigate the inherent, inescapable fragmentation of running the same OS on two very different types of phones.

RIM has faced down that last problem before, with both the BlackBerry Storm catastrophes and the wayward Torch line. But it’s hoping it has a better answer this time around. It’s is similar to what Microsoft is facing with Windows RT and Windows 8, but made more complicated by the lack of screen space on Qwerty models. The Bold 9900 had a 2.8-inch display. The rumored screen size for the Z10 is 4.2 inches. Design language just can’t navigate differences like that. Probably. Maybe RIM has something remarkable up its sleeve, but however it’s worked out, this will likely be a headache for developers. Which won’t go very far in helping along the next point.

This one’s obvious, but it needs to be said. BB10 will launch with Facebook and Twitter and, uhhh, 69,998 other apps that you don’t know much about. Just looking at raw numbers, that’s a fine start, but if you’ve spent any time on Windows Phone, you know that hundreds of thousands of apps doesn’t replace optimized first party support from the biggest apps people want.

Maybe those key apps are different for the BlackBerry crowd, and Instagram and Spotify’s* (assumed) absences won’t affect BB10 like it they do Windows Phone. But what about more business-facing apps and services like LinkedIn (which is missing from integrated sharing options), or AutoCAD, or even OpenTable and Uber? Most of those apps are traditionally pretty good about getting onto new platforms. Whether they and others like them do for BB10 will go a long way to determining its viability. That necessity is buffered a bit by BB10′s Android app-porting functionality, but it remains to be seen how effective and widely utilised that process is.

Even then, just having an app isn’t enough. We need apps that give a crap. From the top down, developers need to buy into what RIM is doing here. That means optimising for both screen types, Qwerty and full touchscreen. It means building deep functionality into the Hub feature, and not just supplying surface level information there. It means, basically, going all the way in on this platform and not just putting out a sorta-good-enough lip service app that doesn’t take advantage of all of BB10′s new features. That hasn’t really happened yet on Windows Phone 8 (though it’s getting there). RIM needs to hope devs are more willing to take the plunge with BB10.

*Yes, Spotify was on WP7, but the app remains unavailable on WP8 devices, probably owing to the fact that it was a third party build sponsored by Microsoft.

Price matters on smartphones, and coming out of the gates with a free on-contract handset would be insane. Windows Phone makers have made the gambit of pricing down some of the best phones, like the Lumia 920, to basically nothing. Affordable has been a winning strategy for Android, and it’s even more important for BlackBerry devices, which need to be cost efficient at scale so IT managers feel their pockets cringe when considering a jump to iPhones or premium Android devices.

RIM’s got a long road ahead of it before finds solid ground. But delivering on these four conditions mean it’s not an afterthought any more; it’s a serious part of the conversation. And for RIM, right now, that’s everything.

Z10 render images courtesy Martin Hajek