Currently, a select element with align='center' or align='right' causes the text contained in the button to be aligned center or right respectively. Firefox and Opera always renders the text content left-justified. I once again have not tested in IE6 or IE7.
Created attachment 12163 [details]
Took a look at the testcase in IE6, can confirm text is left justified in all select elements.
Created attachment 12166 [details]
Landed in r18529.
Comment on attachment 12166 [details]
Clear review flag since Sam already landed this.