Server Roles and Collocation:
Archiving and Monitoring are no longer a separate role. Front Ends connects directly to the Archiving and Monitoring DBs
AV MCU cant separate, Always collocated.
Resiliency, Availability and DR:
All user data is now replicated between all Lync servers in the enterprise. So users has a full functions when resilience to the backup registrar.
Lync Server 2013 supports synchronous SQL mirroring on the Back End databases. So, there is no need for the cluster shared storage.
All Lync 2013 Front End servers stores a complete copy of all the databases stored in the SQL Back End. So, they will still function if the back-end SQL database server went down.
IM and Presence:
With Exchange 2013, a unified contact store make users manage their contacts in Outlook 2013, Outlook Web App , as well as in Lync 2013.
XMPP integration built into Front End Servers and Edge Servers, and you can enable it and configure it to allow this feature.
Enterprise Voice and Voice Features:
Inter-Trunk routing is finally supported by Microsoft Lync Server 2013. You can bind two voice systems through Lync, so voice system A can communicate with voice system B passing through Lync Server 2013.
Delegates can setup simultaneous ringing to their mobile devices for incoming calls to their manager.
When a user has setup simultaneous ringing to a mobile phone, and the device is turned off or out of range, Lync 2013 can determine that an incoming call was immediately routed to voicemail, and disconnect that endpoint so the call can continue to ring other endpoints.
Caller ID presentation allows administrators to modify the Caller ID format in a much more scalable way than in Lync 2010.
Similar to Exchange 2010, you can mix on-premises and Lync Online servers.
Voicemail Escape: Lync Online users can make calls via an on-premises PSTN gateway to call PBX extensions or PSTN . Media bypass will work in this situation, so a user’s media stream won’t be hair-pinned through the Lync Online service when making phone calls from an office running a local PSTN gateway.
Exchange Server integration:
You can enable Lync Archiving integration, which integrates Lync Server 2013 Preview Archiving into the Exchange 2013 Preview Litigation Hold feature, for users homed on Exchange 2013 Preview, which enables one common experience for administrators around compliance and eDiscovery.
Lync Mobile enables communication with anyone, no matter where you are. Send an IM, make a Lync call, or even join a Lync Meeting with just one touchfrom a Windows Phone, or an iOS or Android device. Using either a mobile data connection or Wi-Fi. Stay productive on the go with voice and video over IP, PowerPoint sharing, and more collaboration capabilities.
Group Chat Persistent Chat:
Persistent Chat is the Group Chat trusted application and is now Server Role added from the Topology Builder and no separate client is needed.
Integrated Administration Console
More enhancement in Response Group
H.264 SVC codec support to enable HD video conferencing across a range of devices
Video Gallery feature to simultaneously displays up to five different participants videos, identifies the active speaker, and associates names with faces. HD photos represent all additional meeting participants.
Both PC and Mac users can now join a Lync Meeting from a browser and enjoy the rich Lync Meeting experience, including multiparty HD video, voice over IP (VoIP), instant messaging, and desktop, application, and PowerPoint sharing.
Full IPv6 support
Extend your reach by connecting Lync users with Skype users. Lync-to-Skype federation opens a new communications door for enterprises searching for inventive and differentiated opportunities for new customer acquisition, customer retention, and business-to-consumer communications.
VDI plugin – allows full A/V support in virtual desktop environments
Windows Server 2008 R2 SP1+ is needed with x64 architecture (Windows Server 2012 is supported).
Some changes to enrich the RBAC
Download Microsoft Lync Server 2013 Preview: Registration Required.
Download Microsoft Office 365 ProPlus Preview: Lync 2013 is part of it.