UPDATE (December 12th, 2014): Exchange 2010 SP3 Rollup 8 v2 is released, addressing the issue mentioned below in the initially published version. The new version number is 14.3.224.2 (was 14.3.224.1). You can download RU8v2 here.

UPDATE (December 10th, 2014): Exchange 2010 SP3 Rollup 8 has been pulled after discovery of Outlook MAPI issues. It is currently recommended not to deploy RU8 and when you have installed RU8, to revert to RU7 to prevent walking into this issue. Other protocols, such as EAS or IMAP4, as unaffected which is why you might not encounter this problem immediately.

Today the Exchange Team released Rollup 8 for Exchange Server 2010 Service Pack 3 (KB2986475). This update raises Exchange 2010 version number to 14.3.224.1.

This Rollup contains a security update to fix a potential elevation of privilege issue (bulletin MS14-075), as well as the following fixes:

• 3004235 Exchange Server meetings in Russian time zones as well as names of time zones are incorrect after October 26, 2014
• 3009132 Hybrid mailbox moves to on-premises environment but finishes with CompletedWithWarnings status
• 3008999 IRM restrictions are applied to incorrectly formatted .docx, .pptx, or .xlsx files in an Exchange Server 2010 environment
• 3008370 Group members are not sorted by display name when HAB is used with OAB in Exchange Server 2010
• 3008308 Public folder database migration issue in a mixed Exchange Server environment
• 3007794 Hub Transport server cannot deliver messages when a database fails over to a cross-site DAG in Exchange Server 2010
• 3004521 An Exchange server loses its connection to domain controllers if a public folder server is down in Exchange Server 2010
• 2999016 Unreadable characters when you import ANSI .pst files of Russian language by using the New-MailboxImportRequest cmdlet
• 2995148 Changing distribution group takes a long time in an Exchange Server 2010 environment
• 2992692 Retention policy is not applied to Information Rights Management protected voice mail messages in Exchange Server 2010
• 2987982 Issues caused by ANSI mode in Exchange Server 2010
• 2987104 Email message is sent by using the “Send As” instead of “Send on Behalf” permission in Exchange Server 2010
• 2982017 Incorrect voice mail message duration in Exchange Server 2013 and Exchange Server 2010
• 2977279 You cannot disable journaling for protected voice mail in Exchange Server 2013 and Exchange Server 2010

Notes:

• If you want to speed up the update process for systems without internet access, you can follow the procedure described here to disable publisher’s certificate revocation checking.
• If you got a DAG and want to properly update the DAG members, check the instructions here.
• Rollups are cumulative per service pack level, i.e. they contain fixes released in earlier update Rollups for the same product level (RTM, SP). This means you don’t need to install previous Rollups during a fresh installation but can start with the latest Rollup package.

As with any Hotfix, Rollup or Service Pack, I’d recommend to thoroughly test this rollup in a test and acceptance environment first, prior to implementing it in production.
You can download Exchange 2010 SP3 Rollup 8 here.