..the easiest way to test yor sdcard-hw "today" is to go with my setup (see my post, sanguino like) and to use pb4 as the chipselect (take it from the jumper J3-pin3 and apply accordingly 
)...
sw trap - the biggest issue with arduino is the attempt to make everything "automated" so in the near future the wrappers will be 99% of an application volume... fortunately sw-wise is everything doable.. 
.. I'm currently working with pic32mx so I am observing carefully those guys with chipkit (arduino "clone" based on pic32mx).. they are in much worse situation than you.. 