Oracle and Sun team up to provide .Net alternative

Oracle and Sun are teaming up to provide a "standards-based" alternative to .NET with Solaris 10 and Fusion middleware.
Solaris 10 and Fusion middleware are both relatively impressive technologies with a lot of value, but does that justify the cost and the interoperability limitations that afflict these somewhat isolated platforms? Fusion is an end-to-end solution for developing, deploying, and managing extensible service-oriented application architectures. It is virtually unbreakable, but the price is steep. Solaris 10 provides extreme reliability but it is still very expensive if you run it on Sun's hardware.