Along with lot fields that are post back enable on the form and I do not wish users will face many screen refreshed, I need to have a peopleedit in a updatepanel.  It seems impossible because both [peopleedit] and [updatepanel] are built on Ajax? I am looking for a solution or workaround. Thank you very much for your help.    

I've not used UpdatePanel for years as it's not really efficient. I would prefer a Custom WCF service (JSON enable) and on input fields changes, I would call the WCF service using JavaScript (jQuery/Knockout/Angular).

I think the best/easy option would be to knockoutjs. If you create a viewmodel in knockout and bind it to your aspx/ascx form, your viewmodel method/property will be invoked/changed automatically as user changes them in the form. I think it's worth investing time in WCF/JS based approach.