Apple says this can be a reason for rejection for any Iphone app:

*No Interpreted Code
You cannot create an app that downloads and executes code that was not present in the app bundle submitted to Apple.*

So that means downloading Html code from my webservice to give some style to my app is not allowed?

Also other than Html do you think it s allowed that I can download layout hints from a web service? for instance I have a dynamic questionarry to be downloaded from web service and every question has its own layout e.g the textboxes width and layout, which control to use (datepicker or textbox)..so app will look different than they accept in the app store. is this allowed?