If you're making the move from Oracle to SQL Server, here are my thoughts on the major differences.

1. SSMS is so much faster and more capable than Oracle Enterprise Manager, which is uber-slow.

2. SSMS replaces both Enterprise Manager and SQLPlus.

3. You cannot create packages in SQL Server.

4. There's no tnsnames.ora or sqlplus.ora in SQL Server.

5. There is no TO_CHAR.

6. In PL/SQL development, you WANT to use cursors because of how they're handled in upper memory. In t-SQL, you DON'T want to use cursors because they're very slow. The numbers table approach is still a great way to go for set-based programming.

7. I think you'll find .NET to be an order of magnitude better than Oracle Forms and Reports. I was very happy to say "goodbye" to them - they were powerful, but also excruciatingly painful.

These are just the highlights and only represent my two cents, but the differences are many.

HTH