Q:

IE8: drag'n'drop files to a webpage

Is it possible in IE8 without using third party plugin like Java? 

A:

Short answer : no
Long answer : how to determine the presence of HTML5 drag’n’drop file upload API

A:

That's a standard HTML5 feature, only supported by Chrome 4+ and Firefox 3.6+ so far.  But as for IE8, expect it to be included (and working properly) by the next millenium.