Some features are deprecated from next version of SQL Server 2008, here are some of the commons used functions which are deprecated and their replacements.
Look at BOL for more info
As we know that grouping set is union of different result sets generated by group by clause. Here in group by clause we can use also cube and rollup functions.
Its a new feature in SQL Server 2008. It generate a result of union all of group by result of different set of columns.
We can also use cube and rollup function with grouping sets.