I've been wanting to get rid of the colons because when writing javascript widgets for Greenpeace I couldn't figure out any way to use a colon in a javascript variable. In fact being able to include a colon in an identifier is fairly unusual.
So I used double-underbar for the "__refreshing_p" hidden var.
dot often has special meaning in other languages so I think I'd favor use of double-underbar, since underbars are commonly supported and especially since they cause no problems in JavaScript ...
