Microsoft on Thursday announced that Skype will be available later this year for devices powered by Amazon's Alexa voice assistant.

The deepening integration of Microsoft and Amazon's services puts Cortana, Microsoft's own personal assistant, in an awkward spot.

If you have both assistants at your disposal, there are fewer reasons to talk to Cortana as Alexa becomes increasingly useful.

Microsoft's Skype has waned in popularity over the years, as newfangled video chat tools like Apple's FaceTime and Facebook Messenger have stolen the spotlight. But Skype still has many fans — after all, it's the only video chat tool built into Windows 10 PCs and the Microsoft Xbox One console.

So it may come as a pleasant surprise that Microsoft today announced that Skype will be available later this year for devices powered by the Amazon Alexa voice assistant. If you have an Amazon Echo speaker, or any other Alexa device, you'll be able to make calls to your Skype contacts just by saying, "Alexa, call Bob on Skype." It even works with video calls, if you have an Alexa gadget with a screen.

It's a further development in the unlikely partnership between Amazon and Microsoft in voice computing.

Just recently, the two companies delivered on a long-promised integration that would let you use Alexa to talk to Microsoft's Cortana voice assistant, or vice versa, on any device that supports either assistant.

The big idea, the companies said, is to play to each of their own strengths: A user speaking to Cortana on their Windows 10 PC might want to use Alexa to shop with Amazon; an Amazon Echo owner could use Cortana to access Microsoft-specific services like Outlook and, well, Skype.

Now that Skype is available for Alexa, though, it raises an uncomfortable question for Microsoft that has been asked all too commonly, recently: What's the point of Cortana?

Cortana is built into every single Windows 10 PC for consumers, sure. But with the PC industry continuing its slow-and-steady decline, there's not a ton of opportunity for growth — and efforts to take Cortana beyond Windows, like the Windows 10 Mobile operating system or the Harmon Kardon-made Invoke speaker, have faltered.

All the while, companies like Amazon, Google, and most recently, Apple, have made significant inroads with their own voice assistants.

The demand for Amazon Echo and Google Home speakers are still only a blip compared to that for smartphones, but they're growing fast, even as their makers double down on the market — Amazon announced a barrage of new Alexa gadgets on Thursday. For its part, Apple's HomePod smart speaker is still not a huge market success, it seems, but the Siri assistant that powers it makes its home on every iPhone, Apple Watch, and iPad the company sells.

Microsoft, though, can't say it has much room for growth with Cortana. The company hasn't backed down from Cortana, exactly — it's still a big part of Windows 10, and Microsoft has made a point of highlighting how Cortana powers certain AI features in the operating system, going so far as to test out a face-lift to the Cortana interface.

At the same time, though, Microsoft is bringing so many of Cortana's most differentiated capabilities to Alexa. Indeed, just recently, Microsoft announced that you can use both Cortana and Alexa to power an Xbox One console on or off with your voice. With that being the case, there are fewer reasons than ever to talk to Cortana, as Alexa gets more useful.

Ultimately, Microsoft isn't showing any signs of giving up on Cortana. It is, however, showing all the signs of being caught in the middle with the Cortana voice assistant, with no obvious way forward. Still, the good news for Microsoft fans is that the company has a big hardware event coming up — an event that could provide more clarity.