It depends what the value in that element is (an unknown), wrapping it in () is the safe route to account for possibly of no input being there.
Edit: Now that you've cleared up it's JSON, this isn't valid:
eval('{"10000048":"1","25000175":"2","25000268":"3"}');
But this will result in a valid object being returned:
eval('({"10000048":"1","25000175":"2","25000268":"3"})');
//effectively:
eval('return {"10000048":"1","25000175":"2","25000268":"3"};');
Picture in a JavaScript file:
This is going to fail, it's just an object declared inline but not proper syntax...the same reason a server has to support JSONP for it to work.
A bit tangential to the question, but since you're including jQuery, you might as well use $.parseJSON() (which will use the native JSON.parse() if available) for this:
var strJson = $.parseJSON($("#status").val().replace(";",""));