The next cumulative update is available. It is still highly recommended to install SP1 before you install post SP1 updates.
KB articles are having sometimes a bit delay but the download of the fixes are possible.
MSF2010: 2598373 The full server package for Microsoft SharePoint Foundation 2010 http://support.microsoft.com/default.aspx?scid=kb;EN-US;2598373
Download link: http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=2598373&kbln=en-us
SPS2010: 2598354 The full server package for SharePoint Server 2010 and contains also the MSF2010 fixes so you need only this one package. http://support.microsoft.com/default.aspx?scid=kb;EN-US;2598354
Download link: http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=2598354&kbln=en-us
Important for all Server Applications listed above: After applying the preceding updates, run the SharePoint Products and Technologies Configuration Wizard or “psconfig –cmd upgrade –inplace b2b -wait” in command line. This needs to be done on all servers in the farm with SharePoint installed. You can run psconfig in parallel on all SharePoint machines.
My post for June 2011 CU and SP1: http://blogs.msdn.com/b/joerg_sinemus/archive/2011/06/29/sharepoint-2010-sp1-and-post-sp1-june-2011-cu.aspx
Post made by my colleague regarding a rerelease of June 2011 CU: http://blogs.technet.com/b/stefan_gossner/archive/2011/07/12/june-2011-cu-for-sharepoint-2010-has-been-re-released.aspx
Posts by CAPES: SharePoint 2010 SP1 and the June Cumulative Update for SharePoint 2010
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