Service Pack 1 for Microsoft Office Filter Pack 2010 (KB2460041) has been recently made available to download.
The Office Filter Pack is a pre-requisite for Exchange 2010, as described in this post from the Microsoft Exchange Team:
Starting with Exchange 2007, installation of the current version of Office Filter Packs is a prerequisite. For Exchange 2007 and Exchange 2010 RTM, the pre-req was 2007 Office System Converter: Microsoft Filter Pack. In Exchange 2010 SP1, this was updated to Office 2010 Filter Packs. The filters are used by Exchange Search to index email attachments on Mailbox servers and by the transport rules agent to scan attachments on transport servers. The filters are also important for discovery searches in Exchange 2010 – Multi-Mailbox Search uses content indexes generated by Exchange Search.
Service Pack 1 (SP1) for Microsoft Office Filter Pack 64-bit Edition contains new updates which improve security, performance, and stability. Additionally, the SP is a roll-up of all previously released updates.
You can get specific information about this update in the Microsoft Knowledge Base article Service Pack for Microsoft Office Filter Pack 2010 (KB2460041) 64-bit Edition.