Replace default words in exposed filters
I have tried to resolve from backend/server side, but without success, so I have reviewed a way using Jquery (client side), while an backend alternative is achieved:

&lt;script&gt;
$("#here-field-name option[value='All']").html("Anytext");  
&lt;/script&gt;


Also, here is alternatives from backend perspective, maybe are useful for you how to default value to select list CCK with form_alter

I hope information be useful.