SQL Server 2008 SP2 is scheduled for release in Q3/CY2010.
SQL Server 2005 SP4.
Yes there is going to be one.
Expected release data is in Q4/CY2010.
Based on current support volume as well as the fact that SQL Server 2005 will enter into extended support on 4/13/2011 we anticipate this to be the last Service Pack release for this SQL Server version. Extended support for SQL Server 2005 will be available through 4/12/2016. Please see http://support.microsoft.com/lifecycle/ for specifics.
The SQL Server team will carefully monitor customer feedback as well as support volume to re-assess our decisions based on your needs.