.NET is a fine alternative in 80% of the use cases. Honestly, in half of the projects I see coming through, the only reason java is a requirement is because everything else is already in java; the only hang up is DB2/MSSQL/Oracle drivers.
.NET is never a good option to Java. The CLR suffers the same performance issues as the JVM and as noted in the thread above people are starting to migrate back to C++ as a result and yet .NET has the further restriction that it only runs on Microsoft systems. So with .NET I get the disadvantages of Java combined with the restriction of not being to migrate to other platforms. That's not a good deal for the enterprise.
