Gotta love this quote...
"Unlike J2EE middleware, .Net doesn't do much beyond connecting information to the Windows desktop. Companies have moved beyond merely connecting applications but now also require software that manages high-volume transactions and all kinds of customer data. They need to integrate complex business processes and centrally automate the management of IT environments. These are all areas where Microsoft continues to fall short. "
Huh...I came from a J2EE middleware environment, is this guy insane? In my experience, J2EE is MUCH harder to get to integrate successfully with 'other' systems (i.e., don't natively use JAVA) than .NET - oh, and don't get me started on trying to use J2EE with CORBA.
The High Volume argument is one which has been around for SO long and has been reported very widely - I have yet to see a comparison of .NET versus J2EE IRL - most of these are purely anecdotal and purport the '.NET garbage collection is inefficient and doesn't scale' argument - never seen proof though which is a little suspect...
The fact that he's an AS/400 guy (and has therefore almost certainly never event opened VS.NET in his life ) probably says a lot. It's not that I'm a .NET fanatic, I just detest these  types of article which have little basis in fact yet are presented as absolute gospel.

UPDATE: Eric Gunnerson commented that he believed that some of the comments I mentioned above were based on an article in PC Magazine... I think it's this one...,4149,1218682,00.asp which is in itself very interesting - this comment was very telling:

"The .NET path offers fewer options in building business logic and database components. Microsoft has no official blueprint for business objects comparable to Enterprise JavaBeans (EJB), though it recommends best practices on the Web (www The .NET developers have to devise their own component models based on these practices, while a J2EE developer just needs to run a wizard to get EJB."

Yup, I agree, Microsoft has NOT provided great architecture resources - before there's any complaints pointing the the MS Architecture site - check out Sun's it blows it out of the water!
In J2EE you had very clear patterns which you could follow - want a web app, look at the MVC pattern - want enterprise integration, look at EJB, stateful or stateless... .NET has ASP.NET and it has the Enterprise Frameworks - what I've never felt in .NET is that these were 'joined up' - and no, I don't believe at this juncture that Whidbey will address it either.

The samples on the ASP.NET site are really interesting they're pretty lightweight web apps - where's the link to .NET Petshop or Nile? I believe this is a hangover from the ASP days when ASP developers were seen as 'Web Developers' and VB6 / VC6++ developers were the 'Application Developers' - this has carried forward to .NET where ASP.NET developers are seen as separate from the 'Enterprise' developers using Interop, Enterprise services etc...