What will the UC industry look like in 5 years?

It's always hard to predict the future. Better to look at where we've been going an extrapolate. When it comes to collaboration tools, rarely does one completely give way to the next. For example, despite saying "e-mail is dead!" for the past 2+ years, e-mail is still the primary collaboration tool for most business use.

For Unified Communications, I think it is reasonable to expect a hybrid approach will be the norm in 5 years: some enterprises will consider deploying only cloud-based UC services (whether through their telecom service provider or another cloud service provider). Some enterprises will want to keep everything in house. Many PBX, IP PBX (and yes, TDM) systems will still be in use as the sunk costs make it too painful to just rip-and-replace them altogether. Many enterprises will deploy more complex on-premises UC middleware (like IBM Sametime or from other vendors) to integrate their heterogenous systems and devices. And still others will want to integrate across on premises and cloud services, and across different vendors' offerings. This final one is key, as interoperability will continue to expand as open standards and APIs take deeper hold.

To help manage this complexity, I think we'll see the rise of both appliances as well as cloud services to simplify for SMBs or entry-level UC, and the continued growth of UC middleware to integrate heterogenous systems.

And finally, I think we'll see much deeper integration of unified communications within the broader collaboration environment. Voice is ultimately just one other way to collaborate, along with e-mail, team spaces, social networks, etc. Keeping voice "separate" makes increasingly less sense.