SQL Server 2005 includes a lot of changes to help make moving from Oracle to SQL Server easier, these include;

- User Schema separation

- Multiple Active Result Sets (MARS)

- Synonyms

- Recursive Queries(CTEs)

and some other smaller issues. However there is one feature if you have any serious Orcle development, especially as an ISV, that SQL Server is missing, and thats sequence objects(this also applies to Interbase customers looking for Generator replacements).

Well I found this old post from the SQL Server Customer Advisory Team that has a good discussion.