I posted something on this starting on October 28, 2008, under the thread title "SELECT Trial Suspended: selenium and vitamin E."
The bottom line for me: it appears that the researchers most unfortunately selected forms of vitamin E and selenium that were not the forms that have the hoped for good effects. (There are a number of forms of each, and they are not all that similar.)
That leaves us with continuing uncertainty. Personally, I'm still taking the yeast-based selenium I decided to start taking shortly after diagnosis for a challenging case of prostate cancer a little more than nine years ago. I'm also continuing to take the vitamin E that I've been taking for about as long, but it has always been vitamin E that emphasizes the gamma form (of tocopherol), rather than the alpha form. My impression is that some alpha is not bad if balanced by ample gamma and delta.
The state organization of which I am one of the directors is continuing to recommend these supplements, but clearly this is an area where we are going to have to make our own decisions in the midst of substantial uncertainty.