Here is an unofficial list for the USA Olympic Trials steeple. I compiled this list from trackandfieldnews's annual lists for 2007 and 2008, plus some additional performances that I tracked down from recent big meets. If you know of anything that’s missing, feel free to add to it, as well as with performances over the coming weekends (up through 6/14/08, the end of the qualifying window).
Slattery, Olinger, Aguayo, McAdams
Olympic A Standard - 8:24.60
Fam, Brooks, Lincoln, King, Spence
Trials A Standard (Olympic B Standard) - 8:32.00
Bruce, Nelson, Nowitzke, Smith, Davis, Alcorn, Fife, Olson, Watson, Chorney, Warrenburg, Ptacek, Meyer, Goodwin, Janson
USATF field size of 24
Slosky, Salberg, Gray, Martinez
This is a list of only 28, but this is all of the guys that have broken the Trials B Standard (8:45.00). The last performance on this list is 8:44.92. I'd be surprised if any of these guys opted out of the steeple in favor of another event.