Microsoft today released a technical preview of new Skype for Business voice and meetings capabilities in Office 365. The new features are actually available as part of three separate previews, which Office 365 enterprise customers can choose to trial separately or together: Skype Meeting Broadcast, PSTN Conferencing, and Cloud PBX with PSTN Calling.

Microsoft launched Skype for Business in April, and began upgrading customers using the Lync 2013 client and the Lync Online service. A month earlier, however, the company promised to launch new enterprise features in preview “this summer.” That time has finally come.

BJ Haberkorn, director of Skype for Business product marketing, told VentureBeat the company is hoping to have all three features out of preview by the “end of calendar year.” While the previews are free, Haberkorn admitted the company isn’t sharing pricing or licensing details just yet.

Skype Meeting Broadcast, which lets you broadcast a Skype for Business meeting on the Internet for up to 10,000 people, is available in preview to Office 365 customers worldwide. Attendees can join via their desktop browser or mobile device, and participate in real-time polling via Bing Pulse and chat via Yammer. Haberkorn explained he expects this feature to be used for virtual town hall style meetings as well as public webinars.

PSTN Conferencing, which lets you join a Skype for Business meeting in Office 365 by dialing in and add someone by dialing out to their landline or mobile phone, is available in preview to U.S. Office 365 customers only. It is meant as an offline alternative; online meetings can include people in places with no Internet access.

Cloud PBX with PSTN Calling, which lets you make and receive traditional phone calls in Skype for Business, is available in preview to U.S. Office 365 customers. The Skype for Business client can manage calls with features like hold, resume, forward, and transfer thanks to the enterprise voice technology available in Lync Server and Skype for Business Server. The feature will ship worldwide this fall with an option to use existing on-premises phone lines for inbound and outbound calling.

Office 365 users will thus be able to leverage Skype for all their written, audio, and video conversations. “The Office 365 Skype for Business voice and video services are based on an intelligent real-time network, spanning Microsoft’s global data centers, to deliver secure, high-quality voice and video traffic at the speed of light across the globe,” Microsoft said in March.

Also at that time, Microsoft revealed it had partnered with AT&T, BT, Colt, Equinix, Level 3 Communications, Orange Business Services, TATA Communications, Telstra, Verizon, and Vodafone to help deliver direct connections to Office 365 Skype for Business customers through Azure ExpressRoute for Office 365. Today, Microsoft’s only update was that these direct connections would come “later this year.”

ExpressRoute lets enterprise customers create private connections between their premises and Microsoft data centers. The goal is to offer more predictable network performance, better network availability management, and improved reliability.

All in all, these previews deliver a lot of new functionality. Haberkorn told VentureBeat he hoped that because Microsoft’s solution would bring the communication stack right into Office, enterprises would be able to eliminate their separate meeting systems and PBX systems.

Indeed, Microsoft is playing its cards well. It is wooing existing customers with free previews, and down the road the company will reveal pricing according to demand.

Update on July 7: Microsoft today expanded Skype for Business services in Office 365. 14 additional countries now have access to the preview, and Cloud PBX is available worldwide. Number portability and voicemail are now available in the U.S.