The R2 update for Windows Server 2003 was mostly about bug-fixes plus the odd feature tweak, but that's not the case with Windows Server 2008 R2. Expected around October, Windows Server 2008 R2 is a far more important release with a lot more in the way of new features and functionality than you might normally expect from this kind of mid-term update

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Windows Server 2008 R2: A first look