One of the big deals for us with Visual Studio 2008 is the fact that our runtimes are in the box.
A key thing that this means is that every Visual Studio user now has our powerful T4 text templating engine installed and can incorporate code generation into their development process. That's right - Visual Studio now has code-gen built-in baby. Oh yeah. (See - the USA lingo is catching already)
That means you can add code gen to any Visual Studio solution, whether it has anything to do with Visual Studio eXtensibility or DSL Tools or not - it's just there.
However, as with most good things, there's a slight catch. We didn't have time to get an editing and development experience for T4 templates into the product.
Happily, our friends over at Clarius have been working away and come up a spiffy editor that you can add on. A beta is currently available for Visual Studio 2005 and Visual Studio 2008 Beta2. Hopefully they'll update the 2008 version for RTM shortly (see I'm nagging again ;-) )
Go download it at http://www.t4editor.net/
As folks start to notice this new Visual Studio 2008 feature, I'll be fascinated to see where it starts to crop up.