Update: At press time, Slack announced a new feature called Slack Calls, which is available on both the desktop app and within Chrome.

It was only a matter of time before Slack took over everything.

I've been predicting this one for a while, mostly in the context of business collaboration and an email replacement. Slack announced at a customer conference recently that they plan to add voice calls and video chat to the popular service.

Why is that a big deal? Let's start with some data. About 2M people use Slack everyday in their jobs, sending private messages to each other, chatting in groups, posting photos that are saved in an archive in perpetuity. They ramped up quickly to a $1B valuation and 8,000 customers. There is a lot of buzz that Slack could go "mainstream" in the sense that it becomes more than just an email replacement for business and literally changes how people communicate at work.

And then there's the possibility of widespread consumer adoption. Think about how you communicate with colleagues today and then how you communicate with friends and family. They are very different. Many of us use Facebook for chat, but that's mostly for private exchanges. (The chats are not searchable or in a hub.) You might send an email or text, but few of us use Slack to talk to our spouse and kids.

The new Slack features could change that, because it moves Slack from simple text-based collaboration to real-time communication in any form--text, voice, or video. The old way--using Skype or Facebook--are not stored in a central hub where you can easily go back and see that your boss didn't just chat with the team, he also called Mary in accounting and held a video conference. The "hub" is the big selling point because it exposes (to use a slightly negative word) the communication.

I've heard of many companies who have almost ditched email entirely because of Slack. Now, it might make sense to ditch Skype, your phone network, and several other apps. The hub is getting bigger and more useful.

What's left? Slack hasn't made a move into cloud storage, but I'm expecting that, too. It would be a bit backwards, since companies like Dropbox have added some collaboration tools to the core storage offering in recent months. How about presentations? Word processing? Whiteboards? All-hands meetings? The sky's the limit, once you get hooked on the text chat and image sharing.

The good news for startups is that it means a lot less hassle in terms of managing a bunch of apps and a network infrastructure. Skype is a bit of a pain for some small businesses, especially since that tool started as a consumer video chat product and now dabbles in business conferencing. It's another app to install and manage. There may be no reason to use it anymore, if Slack has their way.