I like the look of some of the Jquery validation plugins as opposed to the ASP.NET validation controls.
However, one big benefit of the ASP.NET validators is they automatically work on the server side too. Hence saving time and saving validation getting missed when work is maintained.
I am wondering if anyone has come across any tool/plugin to assist in automated mapping of jquery client side validation to a server side fallback.
You might want to have a look at this. It's in MVC 2, but it's about using data annotations on both client and server side - there's nothing to stop you rolling your own method for this at present. There's also a framework called xVal, which I believe does something similar.
I was working on a method to do this, and it works for most basic cases (doesn't support ValidationGroup yet)... you could extend my source code to do what you needed, maybe I will be motivated to finish it.