I've checked it the attached patch which allows one to issue

	-var-update @

and have all @-varobjs (or floating varobjs, as Nick suggested to name them),
updated. I believe this is the only reasonable way to make @ varobjs, which
are not bound to thread/frame/block to adequately work in MT program. Otherwise,
if frontend switches thread or frame and wishes to update floating varobjs,
it should either to "-var-update *", which is extra work, or update varobjs
one-by-one, which is also not very nice.

- Volodya

2008-03-26  Vladimir Prus  <vladimir@codesourcery.com>

	* varobj.h (varobj_floating_p): Declare.
	* varobj.c (varobj_floating_p): New.
	* mi/mi-cmd-var.c (mi_cmd_var_update): When passed
	'@' as the name, update all floating varobjs.