IronPython and ASP.NET
Keep a look out for ASP.NET MVC
The IronRuby guys have got some internal builds of MVC to work with IronRuby, and IronPython 2 and IronRuby have a lot of code in common with the DLR.
I'm not sure if they'll support IronPython/IronRuby when MVC is released, but it's definitely worth keeping your eye on anyway - The old ASP.NET forms-based development model is old, busted, and the sooner it goes away the better.
Has anyone built a website with IronPython and ASP.NET.  What were your experiences and is the combination ready for prime-time?