I stumbled upon a a technical white paper that provides a feature comparison between MSSQL 2005 (Yukon) and Oracle 10g databases. Here are a few points I noted from the paper, quoting:
MSSQL database was and still is several steps ahead of Oracle in such great features like the ease of installation, configuration, performing basic tuning and the use of development tools.
The important limitation of Oracle always was the need for a highly skillful Oracle DBA, while almost every experienced MSSQL developer can perform DBA role successfully.
Oracle 10g â€œdata gridâ€ in reality is nothing more than just another buzz used mostly in the business, since Oracle 10g supports grids of 4 to 8 instances on most platforms.
Unfortunately data pump output is yet another proprietary Oracle binary format.
MSSQL databases structure is simpler and designed better than Oracle tablespace.
Implementation of something similar to MSSQL Identity by using Oracle sequence would require reflecting the sequence name in the application or creating a trigger for each table/sequence pair.
The authors also write about major limitations of MSSQL prior to Yukon, useful Oracle features that will have no compatible features in MSSQL 2005 and useful MSSQL features that have no similar features in Oracle 10g. Read the full paper here (PDF).