nagir

Maybe it is not about Helpers, but rather user controls... 

I share this opinion.  Helpers are helpers, not ServerControl replacements.

nagir

I don't believe it's possible to write GridHelper that would produce the grid with the same functionality for ExtJS, jQuery, Prototype.

I hope to prove you wrong then... Although as noted above, I don't think a GridHelper is the correct use of a helper, but we will see.