Well duh.

Perhaps I wasn’t very clear; LINQ can use XML or .xls as data sources, not just as output options. This is the game-changey part.

I’m not saying LINQ isn’t awesome: it certainly seems awesome. I wouldn’t necessarily call it a “game-changer”, but I imagine if I were working in .NET I’d think it were pretty damn awesome.

But since I’m working in RoR (when I’m not stuck in PHP-land), your RoR example is pretty basic. It’s just an AR::find operation. You could very easily call .to_xml on that find result and get back an XML document. Or .to_yaml. And extending ActiveRecord::Base with a to_excel method that spits out an excel file would only be as difficult as writing the excel file–that is, extending AR is drop-in-the-bucket simple.

To your “can’t build programatically” point: You can’t assemble an AR find call easily, no. But you can do some ridiculously awesome things using named scopes, which are extensions to a particular model. LINQ looks like it just makes it easier to scatter data selection operations willy-nilly around your code without respect to domain objects or organization.