GUID

I know I'm probably being a bomb tosser, but would it be practical to
incorporate, like the serial type, and automatic GUID type?

While I love PostgreSQL, I am frequently forced to deal with Oracle and
MSSQL. While there is a great deal of focus on making PostgreSQL a good
competitor to  Oracle, making it a good competitor for MSSQL is a good
idea as well. (Yes, I know this is not a very difficult target.)

The reference code is readily available and postgresql functions are
trivial to write, if one were to submit code properly addorned with the
various copyright notices, could it be included in the main catalog?